Bug- Musescore 4 crashes when I try to "reveal" parts.

I am working on a jazz orchestra arrangement of my own, and am trying to export the files to print. I am wanting the Rhythm Section to have the Lead vocal part on their chart alongside their instrumentation, but as soon as I try to "reveal" the instrument into the part I am working on MuseScore instantly crashes.

Any thoughts on what I can do?

Many thanks! :)