Performance alert

We have 2 XGs in HA mode (a/p) based on SG210 hardware. SFOS 17.5.4 is installed. Both systems are up since 14 days now. Memory util is stable at 37%, cpu util is somewhere between 3% and 14%. It sometimes increases to 20%. System util is just below 4.0 (whatever that means).

The performance icon on the dashboard shows up in orange color but I don't really know what's the problem. Where can I take a look at? Didn't have this during the last 18 months.