[Solved] System hangs

[ppreininger]

Hi,
I've got a Fitlet2 running with
OPNsense 20.1.8_1-amd64
FreeBSD 11.2-RELEASE-p20-HBSD
OpenSSL 1.1.1g 21 Apr 2020

At least once a day - I can't tell for sure - around midday - the system hangs (the last system log entry was at 12:34). I've got another filter2 running with a similar configuration without any problems. The hanging one is a new one.
I can't see, where the problem would be. Is there something I can turn on for verbose debugging or similar? When the system hangs, I can't even access the system via screen/keyboard. 

[ppreininger]

The problem was an EMC problem. grounding the device did the trick...