OH3 - Network gone - no way to recover

This network crash issue (incoming connections are not working - sometimes mainUI is still ok - see above) is really annoying and I have followed some other threads about similar issues.
There are a few rough ideas which might be related to this issue:

  1. Corrupt file system: Originally it happend on my SD-card, but it’s happening now also using the SSD
  2. Low voltage: Slow zwave (USB) and SSD (USB) cause the SSD to disconnect (?)
    (network disconnect was also mentioned for RPi1-3, but the RPi 4 Ethernet is not connected via USB bus). I am using the official RPi4 Power supply. Furthermore the red LED is solid ON.
    side note: The SSD was connected as backup, even when running from sd-card.
  3. One thread mentioned the zwave stick beeing not connected properly to a RPi4 (via USB2), but this does not seem to be the case on my setup (it connects properly to /dev/ttyACM0).

The next step is to start from scratch (what I already did a few times) and just hope.
I bought a brand new SSD and will go for the ZRAM option with UPS.
Usually I am an optimistic guy, but this keeps me awake at night :wink:

Any more ideas are still greatly appreciated!
Thanks for all your help guys!

An important reference is this by the way (thank you for this @mstormi)