After update to latest software formulas get messed up

Currently have installed v4.3.6 win x86, on windows 10. Everything works great. I have a spreadsheet using LibreOffice Calc. I have twice tried to update to latest software and both times, some formula “cells” get messed up. I fix them, come back later to do another operation and I see that what I had fixed has changed back to what it was before, messed up. And yes I save my work every time. Tried this yesterday with v5.0.4, same “messed” up result. Reverting back to previous software fixes the issue. Don’t have a problem keeping “old” version, but sometimes there is a reason a program is updated, besides just new features.
Thanks in advance,