Can't change clef for one (1) measure of a score

I'm shortening a piano piece I found on musescore for performance purposes, just taking out the parts I won't play, and this has created a problem.

Somewhere along the way of deleting chunks of music, the left hand of both parts (it's a duet) changed from bass to baritone clef. I can change the clef back to bass for most of the song, by dragging and dropping, and by double clicking from the clefs palette, no problem. But there's a single measure that refuses to change. I can even drag the bass clef onto the first notes of each part to do a "mid measure change." But the beginning of this one measure is stuck on baritone clef.

I have to go back and fix a lot of the notes because of this, but I can deal with that. I just can't figure out how to change the clef for this measure. None of the original song is in baritone clef so there shouldn't be a reason for the change in the first place.