Your code will not compile for me:
Error CS0127 Since 'FrmMain.SomeClass.RunStep()' returns void, a return keyword must not be followed by an object expression OneOffJobs D:\Documents\AA Backed Up\My Projects\OneOffJobs\OneOffJobs\FrmMain.cs 113 Active
That's running with .NET 4.72 on VS2019
So ... if the code won't compile, then what runs may not match that code.
Either you cut down the code sample too severely to show the problem, or your actual code is running against an outdated class.