Side-step Bug In Musescoore3

I was almost finished a 131 measure choral piece I was arranging for a group.
I had to add a measure and notes about 2/3 of the way through.
The piece was in 2/4 time.
After I had completed the addition of the referenced measure , successfully, I found that the measures after the area reworked had sidestepped. The note or notes corresponding to the first beat of the measure moved to the second beat, and the note or notes formerly on the second beat now moved to the first beat of the following measure! This followed to the end of the score.
I spent hours this morning trying to reverse this bug, and was finally forced to print, delete, and rewrite the balance of the score from the printed, now off set, measures.
Did this bug bite any others?
Art Schubert
Editor/Arranger For The Sierra Canyon Singers
Reno, NV