Teams troubleshooting problems with Excel file

[pieciaq]

Hello,

We share file in Teams (Excel file), simultaneously working on it about 5-6 employees, but sometimes file close or stop to synchronize (autosave is turning off).

But I not really sure how can I troubleshoot this problem?

[#2]

One of your users is possibly locking the file, has auto save off, or is using an older office client version which would cause the file to get locked, which in turn when you open it would have autosave off. If you try to save it with auto save off, it should say someone has it locked and who it might be?

[#3]

@Chris Webb thank You for your response.

All this things you suggest I did but this is not solution for my problems. 

All users user the same version of Office 365, they have turn on AutoSafe, problem accure randomly sometimes after couple hours of using this Excel file. 

I think that problem is size of file about 10 MB, many sheets and data and also we working mostly on laptops Users are working with them on meetings etc. they almost never close opened files or shutdown system, and I think when they move and network is reconnecting between access points in company this file sometimes failed to synchronize.

But I don't know how to check this to be sure.