OH1 PRI3: Suddenly USB access is broken

Hi,
From one moment to the next the USB access in OH1 is broken. At night I turned off all lights using OH and the next morning the coffee machine was not on…

I’ve been running with this setup for almost a year without any issue.
RPI3 with 3 USB connections: Heat metering (dsmr binding), smart meter (iec6205621 binding) and zwave (zwave binding). All three stopped working.

USB ports are configured through udev and owned by root/dialout. Openhab is member of dialout.

From openhab start script:
DAEMON_ARGS="
-Dgnu.io.rxtx.SerialPorts=/dev/USBDSMR:/dev/USBIECB:/dev/USBZWAVE2
-Dosgi.clean=true
-Declipse.ignoreApp=true
-Dosgi.noShutdown=true
-Djetty.port=$HTTP_PORT
-Djetty.port.ssl=$HTTPS_PORT
-Djetty.home=.
-Dlogback.configurationFile=configurations/logback.xml
-Dfelix.fileinstall.dir=addons
-Dfelix.fileinstall.filter=.\.jar
-Djava.library.path=lib
-Djava.security.auth.login.config=./etc/login.conf
-Dorg.quartz.properties=./etc/quartz.properties
-Dequinox.ds.block_timeout=240000
-Dequinox.scr.waitTimeOnBlock=60000
-Dfelix.fileinstall.active.level=4
-Djava.awt.headless=true
-jar $cp $

-console
"

Running openhab as root from the command line (start.sh) does not make any difference.

Extracts from the logs:
2017-04-16 12:59:35.393 [ERROR] [b.z.i.protocol.ZWaveController:349 ]- Serial Error: Port /dev/USBZWAVE2 does not exist
2017-04-16 13:00:33.562 [ERROR] [binding.dsmr.internal.DSMRPort] - Could not open port: /dev/USBDSMR
2017-04-16 12:59:33.285 [ERROR] [iec6205621meter.internal.Meter] - Failed to open serial port /dev/USBIECB: Serial port with given name does not exist

I checked the Zstick in a MAC on OH2, no issues.

To me it looks like an OS issue, but I cannot be sure.
Any pointers are appreciated.

Thanks,
C