Looks like it is because:
SQLEXEC creates cursor with the name "UDFCursor", but grid.recordsource is set to the previous value of sys(2015).
Perhaps this'l help:
lnRes = SQLEXEC( thisform.nCon, lcSql, UDFCursor )

>I have an SPT cursor and I am trying to get the data to showup in my grid but its not working. Here is the code:
>
>

>	lcSql = " Select *" ;
>		+ "  FROM UDFields" ;
>
>	UDFCursor = SYS(2015) && UDFields Cursor
>	IF USED(UDFCursor)
>		TABLEREVERT(.t.,UDFCursor)
>	ENDIF
>	lnRes = SQLEXEC( thisform.nCon, lcSql, "UDFCursor" )
>	IF lnRes > 0
>		q = RECCOUNT()
>		IF q > 0 && record available
>			SELECT UDFCursor
>			.Grid1.recordsource = (UDFCursor)
>			.Grid1.refresh()
>

>
>
>I must be missing something here.
>
>
>Thanks
>Nick Patel