undo (ctrl/cmd z) not working

On Mac (10.14). LibreOffice (6.0.6.2) Issue has been happening before/after updates to both Mac and LO.

The undo/redo option (accessed via menu or ctrl/cmd) on LibreOffice fails far too frequently. It’s making for some very sketchy writing anxiety as if I delete something I can’t undo it (which has happened more often than I care to count scream).

I need to save and force quite the application and re-open for it to “reset” itself but more often than not I’ve already lost something before I realise it’s stopped working.

Any ideas or fixes (PLEASE).
Thx.

edit: when I go to the menu the option is not greyed out it just doesn’t do anything when I click it.

Same issue here when working with Draw 6.2.0 on Arch Linux: undo works for a while, and then something seems to break the undo register after which no actions can be undone.

Same issue here with 6.2.2.2 in Mac OS X 10

Exactly the same issue with Draw 6.2.4.2.0+ on Arch.