Musescore 3.5 repeatedly drops (deletees) last note of a particular measure.

This piece includes descending chromatic lines in several places. At measure 80, the program always drops the last note, intended to be an eighth note on G5. If I put the note back in, it will display the note, and play that note. But, after saving and closing the file; and then re-opening it, the note is gone. Measure 60 is identical, and the G note remains there, while being dropped at M80.
Measure 114 is another repeat, which had been flagged by the program as corrupted when opening the file. I deleted the measure and re-entering the notes, which fixed it. This solution does not work at M80.
Puzzling.