MuseScore stops and is closed when I insert bars. Maybe a Bug?

I use MuseScore 3.6.2 Portable AppImage inside computers with Ubuntu-Studio 20.04.2 LTS (64 bit Linux).
Each time I insert more than one bar in any score, any part but the end, MuseScore stops and it is closed by the system.
I can recover the lost work when I restart MuseScore, but... Without the additional bars.
The only one way I found to work around this is to add bars at the end of the piece. Then, I cut and paste last bars into the empty part to create additional empty space.
But... I don't know if this is "logical". I guess no.
Is it a bug?
Is it something happening just in my system?
Is there someone who had experimented the same?
???
Blessings and Greetings from Chile!!!
JUAN