OH3 Serial Binding failing: "Port is not known"

I am running into issues with the Serial Binding in OH3. It will work for a while, then fail, even after subsequent power cycles. Its failing with

18:41:18.235 [INFO ] [hab.event.ThingStatusInfoChangedEvent] - Thing 'serial:serialBridge:sensors' changed from INITIALIZING to OFFLINE (CONFIGURATION_ERROR): Port is not known

Which seems to be similar to other Bindings issues with the serial port, but in this case I only have one serial device configured, and it worked for a while, then stopped. I have not changed its configuration at all between the running and failing. That shouldn’t cause a lack of locks being available.

If I use a python script to read from the port, that works just fine.

That is exactly the behaviour complained of in other serial-using bindings.

It seems often to be associated with an error recovery action. Other commonalities in environment have not been recognised yet.

In regards to your comment on openhab/openhab-core#1842:

I am wondering if this is actually a permissions issue

Is your openHAB user a member of the dialout group? I.e., if you look in /etc/group, does the line for dialout list the username of your openHAB user? For example, on my system, my user is the only member of the group:

$ grep '^dialout' /etc/group

But permissions are not typically responsible for intermittent behaviour.

If I use a python script to read from the port, that works just fine.

Is your script running as you, or as the openHAB user? If you run the script as the openHAB user (i.e., sudo -u openhab python serialtest.py), does it still work?