Activity log disappeared


Hello All

I have this issue with one of my sheet, where the activity log is empty. It looks like this:

The sheet is months old, but last week it stopped showing the log, it only shows my views the same day I view it and nothing more. In the sheet I can see myself that changes are made, but nothing in the log.

When I click show more it doesn't show anything more:

Please help, activity log is a really important part of my work.

Thank you