Json deserialization into C# objects

While C# supports GUID's JSON doesn't - they are represented by strings instead.

However, that isn't technically valid JSON: the string to the left of a colon character is a field name, not a value, so your JSON example treats each new GUID value as a separate class, and that's a problem:

// Root myDeserializedClass = JsonConvert.DeserializeObject<Root>(myJsonResponse);
    public class HoursData
    {
        public string timeZone { get; set; }
        public List<object> regularHours { get; set; }
        public List<object> specialHours { get; set; }
    }

    public class Ae7da5d640244f7d92215d2298afe650
    {
        public string name { get; set; }
        public List<string> categoryIds { get; set; }
        public List<string> fulfillmentModes { get; set; }
        public string id { get; set; }
        public HoursData hoursData { get; set; }
    }

    public class Menus
    {
        [JsonProperty("ae7da5d6-4024-4f7d-9221-5d2298afe650")]
        public Ae7da5d640244f7d92215d2298afe650 Ae7da5d640244f7d92215d2298afe650 { get; set; }
    }

    public class E6860d3386264ef0035808d7df7bade0
    {
        public string name { get; set; }
        public string description { get; set; }
        public List<string> itemIds { get; set; }
        public string id { get; set; }
    }

    public class Fe3bfb19Ed734ae4035908d7df7bade0
    {
        public string name { get; set; }
        public string description { get; set; }
        public List<string> itemIds { get; set; }
        public string id { get; set; }
    }

    public class D59853d1Ff64496e3d3908d7fa4d3d0c
    {
        public string name { get; set; }
        public string description { get; set; }
        public List<string> itemIds { get; set; }
        public string id { get; set; }
    }

    public class _650910ed39f5499b74f908d7fbd34052
    {
        public string name { get; set; }
        public string description { get; set; }
        public List<string> itemIds { get; set; }
        public string id { get; set; }
    }

    public class Fc500654Fcdf492b786408d81110c0b6
    {
        public string name { get; set; }
        public string description { get; set; }
        public List<string> itemIds { get; set; }
        public string id { get; set; }
    }

    public class E70efee8Ed504a65C77808d85b0fb03a
    {
        public string name { get; set; }
        public string description { get; set; }
        public List<string> itemIds { get; set; }
        public string id { get; set; }
    }

    public class Categories
    {
        [JsonProperty("e6860d33-8626-4ef0-0358-08d7df7bade0")]
        public E6860d3386264ef0035808d7df7bade0 E6860d3386264ef0035808d7df7bade0 { get; set; }

        [JsonProperty("fe3bfb19-ed73-4ae4-0359-08d7df7bade0")]
        public Fe3bfb19Ed734ae4035908d7df7bade0 Fe3bfb19Ed734ae4035908d7df7bade0 { get; set; }

        [JsonProperty("d59853d1-ff64-496e-3d39-08d7fa4d3d0c")]
        public D59853d1Ff64496e3d3908d7fa4d3d0c D59853d1Ff64496e3d3908d7fa4d3d0c { get; set; }

        [JsonProperty("650910ed-39f5-499b-74f9-08d7fbd34052")]
        public _650910ed39f5499b74f908d7fbd34052 _650910ed39f5499b74f908d7fbd34052 { get; set; }

        [JsonProperty("fc500654-fcdf-492b-7864-08d81110c0b6")]
        public Fc500654Fcdf492b786408d81110c0b6 Fc500654Fcdf492b786408d81110c0b6 { get; set; }

        [JsonProperty("e70efee8-ed50-4a65-c778-08d85b0fb03a")]
        public E70efee8Ed504a65C77808d85b0fb03a E70efee8Ed504a65C77808d85b0fb03a { get; set; }
    }

    public class MenuData
    {
        public Menus menus { get; set; }
        public Categories categories { get; set; }
    }

    public class Payload
    {
        public MenuData menuData { get; set; }
    }

    public class Metadata
    {
        public string storeId { get; set; }
        public string applicationId { get; set; }
        public object resourceId { get; set; }
        public Payload payload { get; set; }
    }

    public class Root
    {
        public string eventId { get; set; }
        public DateTime eventTime { get; set; }
        public string eventType { get; set; }
        public Metadata metadata { get; set; }
    }

I would suspect that you need to go back to where you got that from as it's not right - the GUID value is duplicated as the field name and the ID within the field.
Your JSON should look like this:

{
    "eventId": "",
    "eventTime": "2022-03-08T07:35:33Z",
    "eventType": "",
    "metadata": {
        "storeId": "",
        "applicationId": "",
        "resourceId": null,
        "payload": {
            "menuData": {
                "menus": {
                    "MyClassWithCategories": {
                        "name": "POSIGENT-DEV",
                        "categoryIds": ["e6860d33-8626-4ef0-0358-08d7df7bade0", "fe3bfb19-ed73-4ae4-0359-08d7df7bade0", "1e53b53b-ee16-4205-035a-08d7df7bade0"],
                        "fulfillmentModes": ["DELIVERY", "DINE_IN", "PICK_UP"],
                        "id": "ae7da5d6-4024-4f7d-9221-5d2298afe650",
                        "hoursData": {
                            "timeZone": "GMT",
                            "regularHours": [],
                            "specialHours": []
                        }
                    }
                },
                "categories": {

                    "MyCategories": {
                        "name": "Soup",
                        "description": "",
                        "itemIds": ["c30bfa7f-042f-4297-e46a-08d7df94661c", "b516b115-a3e3-4723-3b66-08d81902cd59", "b0e9784b-9a95-4ec7-c645-08d81d8e0aa6", "c3af2a3a-e653-4f71-c649-08d81d8e0aa6", "1854763b-3ea7-48e9-799f-08d8bd29d0f1"],
                        "id": "e6860d33-8626-4ef0-0358-08d7df7bade0"
                    },
                    "MyCategories": {
                        "name": "Main Course",
                        "description": "",
                        "itemIds": ["b02b2e78-4d33-480b-ae0a-08d7df7ca760", "55e4d1ed-29ec-472e-e466-08d7df94661c"],
                        "id": "fe3bfb19-ed73-4ae4-0359-08d7df7bade0"
                    },
                    "MyCategories": {
                        "name": "Italian Cuisine",
                        "description": "",
                        "itemIds": ["f812490e-0598-480f-dabf-08d7fa4f2954", "ee06d429-0a98-44e5-4ee7-08d7fa77824b"],
                        "id": "d59853d1-ff64-496e-3d39-08d7fa4d3d0c"
                    },
                    "MyCategories": {
                        "name": "Pizza",
                        "description": "",
                        "itemIds": ["20152ec6-b728-4f9e-1ecc-08d7fdb8106f", "00146279-b5c7-4f0e-cbf6-08d8019c8287", "cea3ed3e-76bd-4bc9-5926-08d811f841d3"],
                        "id": "650910ed-39f5-499b-74f9-08d7fbd34052"
                    },
                    "MyCategories": {
                        "name": "kids menu",
                        "description": "",
                        "itemIds": ["1a6747b3-26fc-4cfe-7b27-08d81110f844"],
                        "id": "fc500654-fcdf-492b-7864-08d81110c0b6"
                    },
                    "MyCategories": {
                        "name": "Beverages",
                        "description": "",
                        "itemIds": ["af91f3f4-b902-4e25-e102-08d85e437b29", "38eaa51d-cf50-4f61-3688-08d870eb7628"],
                        "id": "e70efee8-ed50-4a65-c778-08d85b0fb03a"
                    }}}}}}

Which produces much more sensible classes:

// Root myDeserializedClass = JsonConvert.DeserializeObject<Root>(myJsonResponse);
    public class HoursData
    {
        public string timeZone { get; set; }
        public List<object> regularHours { get; set; }
        public List<object> specialHours { get; set; }
    }

    public class MyClassWithCategories
    {
        public string name { get; set; }
        public List<string> categoryIds { get; set; }
        public List<string> fulfillmentModes { get; set; }
        public string id { get; set; }
        public HoursData hoursData { get; set; }
    }

    public class Menus
    {
        public MyClassWithCategories MyClassWithCategories { get; set; }
    }

    public class MyCategories
    {
        public string name { get; set; }
        public string description { get; set; }
        public List<string> itemIds { get; set; }
        public string id { get; set; }
    }

    public class Categories
    {
        public MyCategories MyCategories { get; set; }
    }

    public class MenuData
    {
        public Menus menus { get; set; }
        public Categories categories { get; set; }
    }

    public class Payload
    {
        public MenuData menuData { get; set; }
    }

    public class Metadata
    {
        public string storeId { get; set; }
        public string applicationId { get; set; }
        public object resourceId { get; set; }
        public Payload payload { get; set; }
    }

    public class Root
    {
        public string eventId { get; set; }
        public DateTime eventTime { get; set; }
        public string eventType { get; set; }
        public Metadata metadata { get; set; }
    }