High CPU on "vanilla" RB333

I just noticed a worrisome issue.

The CPU on our RB333 that is used for a small wireless hotspot is going back and forth between 10% and 100% each time it updates (i.e. from winbox → system → resources)

I’m not sure if this is an odd GUI issue or if something else could be causing the CPU to keep spiking.

The RB is not under a lot of load (i.e. it is supporting <20 users on a DSL line) and isn’t doing anything fancy (i.e. no mangle rules) + there are only ~50 connections in the tracking table now.

I just enabled CPU usage tracking so I can get some data vs time.

Update: I rebooted the RB333 (uptime of 42 days) and the CPU load is now back down to 0-4%