Moving from Excel to Only Office or Libre Office issues

I’m moving this discussion from another thread. It originally started on
Beginners: How to download my Win10 to an SSD to run it from there?

For most spreadsheets, moving to LibreOffice or Only Office has been easy. But what is keeping me from going full-on Linux is a spreadsheet issue I’ve not been able to solve.

LibreOffice version
OnlyOffice version

We have a workbook that has several tabs, many pivot tables, and some complex formulas that’s used like a database. A CSV file gets put into it and filters into a bunch of different functions. So far, my attempts to open it into either LO or OO has left me with broken formulas, or formulas that didn’t translate right. The guy who developed this is amazing at Excel on a Mac. He knows nothing about LO or OO. I’m running it on Win10.

If I could find someone who knows how to translate the formulas, that would be awesome! I did find that when I opened it in OO, some code was inserted into the formulas that aren’t in the E formulas. That was on only one tab. I haven’t checked through all of them.

I just figured I’d have to continue with Win10 until I could get this figured out. Maybe run them both off an external SSD until I can get away from Gates.

Any help, tips, or pointing me in the right direction would be profoundly appreciated. I’ve been trying to figure this out over the last several months and on my own, I’m stalled.