Prerequisites:

• An OpenPGP key A with user IDs A1 and A2
• Another OpenPGP key C (used as certification certificate)
• "Show tags attached to certificates" is enabled

How to reproduce:

1. Certify A1 with tag "tagA1" with certification certificate C.
2. Open details of A.
3. Select user ID A2.
4. Click "Certify User IDs".

Expected:
Certify dialog opens and user ID A2 is checked.

Actual:
Certify dialog opens and user ID A1 is checked (and the (hidden) Tags field is prefilled with "tagA1").