numbers rounds where it shouldn’t

Hello

I created a Numbers file in Numbers 3.6.2 under Mac OS X 10.11.6, later opened it in Numbers 12.0 under macOS 12.4, saved it there, then saved it as Number 09 to open it on the mac running 10.11.6 again, where another conversion happened, when Numbers 3.6.2 asked me to either update the file or to work on a copy (I updated it).

After those three conversions, it turns out that in some cells, Numbers rounds some numbers (in some cells) with decimal fraction to integers (570.37 becomes 570). This happens only when the cell contains a formula, even if that formula is nothing but a referral to another cell. It does not happen when simply writing a number into that same cell.

It appears that some corruption to the original file has happened. Would anyone know if there is a way to undo that damage? The file in question is large, contains many sheets with lots of work, it would be close to impossible to set it up anew. A fix would be greatly appreciated.

Thanks!