Hi,
sorry for the delay but we are already in christmas holiday mode.

- You have succesful upgraded to the 3.9.7.2 version?
If yes, please send me the installation log file from the administrator/log folder via PM
- Only the monitoring function has this problem and your backend works otherwise as expected?
- In frontend exist only the problems with the category view page?
Maybe it would be useful to send me login data for your backend via PM. Or at least a link to the site.