Problems with sharepoint synchronization

hello!!

I'm having some synchronization problems related to SharePoint. At my work, we use a very heavy spreadsheet, with about 50~80mb, where several people work at the same time via SharePoint... This usually causes some expected problems such as delays in calculations or fatal errors, but recently there has been a specific error that has been happening sometimes. During the week, one of the 6 people working on the spreadsheet can simply become a "ghost". They can see who is online in the spreadsheet working with them and the others can also see them online... But any and all changes they make will be visible only to them, not only in the desktop version of the application but in the browser version as well, as if they were working on a local version of the file, but online...

We tried to do some things like:
* clear the %temp% folder
* clear the specific Excel folder in %appdata%/microsoft/excel
* check for files that need attention in "Open new file -> Documents that need attention"
* Unsynchronize the Excel application OneDrive/SharePoint from the computer, delete all local files and sync again
* Change the Excel cache option in "Options -> Save -> Cache" to delete every time the file is closed and also clear the cache

But none of this works, the only thing that seems to work to fix the error for the specific person is for someone who is not having this problem to create a copy of the Excel file in SharePoint and rename it... After that, the person's changes appear again for the rest, fixing the error.

The worst part of this problem is that it has no indication or warning. Recently, members of my team lost days of work because they had become "ghosts" and their changes were not being saved, only when indicated by other members who were also working on the same spreadsheet or constantly checking the Excel version via browser can you be sure that your changes are being saved.

I would like to know if anyone has experienced this and how to solve this error

Thank you for your attention!!