Massive jump in file size?

Hi people.

I have an Excel file that lives on a One Drive (Business version), file size was roughly 2MB, today the file became inaccessible on the One Drive as the size has increased to 37.1MB. (One Drive max size is 30MB)

I cannot see why the file has increased in size by nearly 30 time for no reasons, there is no new data, macros or anything else in there, its just well, bigger.

Is there a way or method I can use to find out why this might be? Is it a common issue?

Unfortunately I cannot upload the sheet here as it has business sensation info on it.

Thank you