When I work in Calc, references to other sheets get lost in all cells.

So instead of "=Sheet2.A1" theres "=A1".

This happens to the whole document, not just single cells.
In addition the Bug is only "visible" when you click on affected cells,
because the cells don't get updated right away.

When I close the file and open it again, I see all the errors in the by
now updated cells. But I wasn't able to catch the bug "at work" so to
speak.

For now it seems very random and I can't reproduce it reliably, but it happened
3 or 4 times on different files in the last week alone.

I judge the severity of this bug very high!

I had to recreate complex sheets for my master thesis from backups and redo a full days work because the saved file opened corrupted the next day (as described above).

P.S.:
I'm using version 4.2.7-2 in manjaro linux