Calc: app not responding when attempting Find & Replace (randomly freezes, even on small data sets e.g. 1200 cells, but works fine other times); randomly deletes Conditional Formatting; randomly runs slowly...

OS Mojave 10.14.6, LO 6.4.7.2

I have listed the previous problems together as perhaps they are related?

Occasionally I get a message saying that “Another instance of Libreoffice is trying to access your personal settings” (or something to that effect), so I checked to see whether or not I have multiple versions installed.
I’ve only got one “Libreoffice.app” in the Applications folder that I installed last year, and from memory whence I was prompted whether or not to keep the old version when installing the new one I opted not to, therefore this should not be an issue right?

Here’s a pic of my Applications folder showing just one instance of Libreoffice:

(Edit: activated screenshot -AK)

As a long time user of AskLO, you should know that the question title isn’t supposed to be a long winded affair.

Apologies, however I figured that’s what the character limit is for.
Seemed to make sense to detail the issues in title so as to attract only those with the know-how to deal with it, rather than wasting the time of those trying to help by misleading them with partial information.

As for the “locked” message, I usually just say “yes”, and have not seen it in awhile so perhaps it has cleared. The problem must be something else then I suppose…

The Conditional Formatting really confused me: opened up the file to find all Conditional Formatting simply gone. Had to load a previous Version, and have made a habit of saving Versions often in case it happens again.
I’d link the file but it contains sensitive information