Zyxel 325 v2 never stops, CPU is at 100% HDDs keep spinnig

Hello,

As the title says. In the past few weeks, I have noticied that my NAS never stops, the HDDs work constantly and the CPU is at 100%. I tried to look for any applications that are active but nothing seems out of the ordinary. How can I stop this and how can I diagnose the issue? It is set up with 2 disks as RAID for years and it never happened before.

Thanks,

G