I posted a note with a similar subject line recently and, following the advice I received, upgraded my system and the application in question. Now I am running Linux Mint 19.2 Tina, desktop Cinnamon 4.2.4, and Libreoffice 220.127.116.11.
Calc freezes very often. Not at regular intervals; it can work happily for a couple of days and then freeze several times in a couple of hours (now is one such period). It may seem to be in response to my pressing two keys in very close succession (for example Shift+DownArrow and then Shift+UpArrow), but this wasn’t the case the last time around.
And it’s not generally due to lack of memory. On some occasions System Monitor tells me that a third of the memory is free and stays free. Although on others LibreOffice freezes first and then proceeds to slowly claim all the remaining free memory, then the swap as well, eventually slowing down the entire system.
Is there anything I can do to diagnose the situation when it occurs? Or is reverting to LibreOffice 6.1 (which didn’t behave in this way, I seem to I remember) the only way to get some work done?