Output parameter returning only one character to the frontend among many

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C#

ASP.NET

SQL

The following is the Output Paramter i'm passing from front end to backend 

DbParameter UID = cmdInsertUpdateAcTran.CreateParameter();
              UID.ParameterName = "@UID";
              UID.DbType = DbType.String;
              UID.Direction = ParameterDirection.Output;
              UID.Value = miscVO.PUID;
              cmdInsertUpdateAcTran.Parameters.Add(UID);

Here is the value(i.e output param) that has to be returned to the frontend from backend 
@UID='H0000018201516ANLPV9'

@UID is inserting to the backend properly but the issue here is it's returning only 1st character i.e 'H' to the front end. Rather i need full String

--Thanks

What I have tried:

select @UID=rtrim(Formtype)+rtrim(Slno)+rtrim(YrBeginYrEndID) from #temp


INSERT INTO [Customer15G]
([CustomerCode],[Customer15HDate],[ReceivedBy],[ReceivedDate],[FormType],[YearBeginDate],[YearEndDate], [UID])
VALUES
(@CustomerCode,@Customer15HDate,@ReceivedBy,@ReceivedDate,@FormType,@EnteredDate,@IntCalTillDate, @UID)


Drop table #temp