Tuplet with Grace Note Issues

Measure 74 on this score results in an error: https://musescore.com/albertavery/scores/5390457

"Measure 74, staff 2 incomplete. Expected: 4/4; Found 15/12"

I have attempted to fix it, so I am attaching the original file that I did not fix.
My suspicions are due to the grace notes within the triplets. For some reason MS does not keep the second quarter note triplet. Throughout the score, there were multiple issues regarding tuplets (5-lets, 7-lets specifically) with diddles (tremolo) markings in them. My colleague reported multiple crashes while trying to input 5-lets.

This is what the rhythm should look like:

This is what MS creates:

In addition, grace notes do not display articulations or tremolos.

Currently using Musescore 3 v. 3.0.0.4785