Merging show BUG?

Hey folks
I was playing with my fullboar4 and v3.1.0.
I wonder what am i doing wrong while trying to merge a specific fixture type of previous shows.
1.:Make an new show with 2 fixture types and patch them. Log off
2.: start a new show again and get into the merge show dialog. Select ur first build show (the one with the 2 fixture types). When u will be asked which fixture type u want to merge check any of the two (that one u want to have in ur current show).

After merging is complete u have the 2 fixture types in ur current show although u just selected one type to be merged.

What am i missing?