[zone: pf states] PF states limit reached

[Keishan.Ramdeo]

pfSense sporadically becomes unresponsive displaying [zone: pf states] PF states limit reached on the console. I'm forced to reset the virtual machine to restore functionality.

I increased the state table size from 200000 to 400000 even though the firewall is only hitting 2000 states (not even 1%) during the busiest hours.

Any idea what causes this issue?!