Exit Plug in Enhancement not possible?

Hi Experts,

I would like create an Exit Plug in a Enhancement of Web Dynpro Application but I had the following issue.

In Display-Mode all looks good, but when I change to the edit mode, the Interface option disappears. So I am not able to create a "real" Exit -Plug. I can only choose, as plug type, Standard.

Display-Mode:

Edit-Mode (Enhance-Mode)

Thank you,

best regards,

Lukas