Your printout of the fakesheet is telling you everything you need to know. I think you are trying to use 1st/2nd ending to define where the song ends and goes into the tag ending.

You told BIAB to repeat the first 28 bars after the 1st ending. That is the greyed out area which happens to be 28 bars long. Not to get anymore into specifics of what you did, try this.

1. Delete your 1st/2nd ending
2. Define your song ending at measure 40 (currently 50)
3. Add a tag after 36 to start at 41 and ends at 50

You'll have to change the number of choruses to more than one. You can't put a tag on a single chorus song.

This is what I would do.