calc is unbearably slow for any action

just moving from cell to cell takes seconds, right clicking cell takes a few seconds for a menu to show up, copying anything is slow.

I can’t imagine this to be normal. I have maxed out all the meory settings, I have tried with Java and without, my system is ubuntu, everything completely up to date.

What could be the problem?

Try resetting the user profile. https://wiki.documentfoundation.org/UserProfile