MuseScore 4 crashing issue -- partially solved

Using MuseScore 4, it was crashing on note entry every 1 to 2 minutes. I closed, exited, restarted my linux machine, and retried the process with no improvement. Opened MS4 again, opened the same file, then Exported to MXL. Then I exited MS4, started MS3 and imported the MXL file, and played it. Then Closed MS3, returned to MS4, and was able to work on the same file until I was ready to quit, having experienced no further crashing issue. That took about ten minutes. I wonder if 1) Exporting MXL or 2) starting MS3 is what "fixed" it. Interesting. Or neither.