FieldByName('Value').AsVariant Get "Invalid Variant Type"

[rezasadigh]

I have a table with two columns "Name" and "Value" in SQL Server
Name is varchar and Value is sql_variant. I want to get a record and use the simle sql code like this with a TMSQuery
Select [Name], [Value]
From [dbo].[MMDocFields]
Where [MMDocID]=230591 and Name='C11'
every thing is OK and a can read the "value" field by usual comman like this:
quTemp.FieldByName('Value').AsVariant

Now, I want to use this in a datasnap service but surprisingly when i use in service, it raise an error with message: TDBXError with message RemoteError: Invalid variant type.

I googled but not found any helpful comment.
Can anybody help me?
Win 10
Delphi Seattle update 1
SDAC 6.10.19

[ViktorV]

The specified SDAC 6.10.19 version does not support RAD Studio 10 Seattle.
Please make sure that the issue is reproduced on the latest SDAC 7.3.16 version.
In order to get a detailed answer, please compose a small sample demonstrating the described behavior and send it using the contact form https://www.devart.com/company/contactform.html including scripts for creating database objects.