Anyone else having high memory usage on the 2100 after a few weeks uptime?

We've got a few Sophos XGS 2100 units deployed. Noticing a consistent pattern where available RAM steadily drops after a reboot.

After about 3-4 weeks of uptime, free memory is critically low (<10%). Performance seems okay, but it's concerning. No major leaks in the GUI, and our user/throughput load is stable.

Anyone else seeing this? Known issues or specific services to check?

Our setup:
- Mostly default config
- IPS, web filtering, and basic site-to-site VPN active
- Firmware: SFOS v19.5.2 MR-2-Build734

Tried:
- Restarting individual services (like Web Filtering) - no permanent fix.
- A full reboot clears it for a few weeks, but that's not a solution.