Xymon has stopped updating

Hello everyone

I have noticed some strange behaviour lately with Xymon. The main page gets stuck and does not update itself.
At the moment it's stuck on the 28th of April. Last time it happened I realised it after 4 days.

The only fix is to reboot the xymon server. I can't see anything in the log files. All I see is the xymon service getting restarted.
Any suggestions please? If you have any ideas please let me know.

Many thanks
Yanni