Hello Andre,
I did not found a solution for this Problem to copy values of text fields but a work arround .
(I wonder a little bit, because I in some webinars it looks like this way of working is possible )
So I avoided to use text fields defined in SAP Screen Personas flavors for parameter value copies.
If I use text fields with data types defined in SAP calling Transactions in the flavor it run well.
The benefit of this approach is also: It's easier to use the standard value help option, which is avaialble in SAP Screen Personas Flavors automatically..
Best regards
Adrian