I’m using OH3 and also have that problem and found out that when activating the smartmeter “Thing” the output of the “dmesg” command gets flooded by input overruns like the following :
[151762.159243] ttyUSB0: 2 input overrun(s)
on the USB-port used by the smartmeter binding.
After a few hours OH3 becomes unstable and must be restarted or my Raspberry PI must be completly rebooted.
When deactivating the smartmeter “Thing” in the OH3 GUI these messages completly disappear and
OH3 runs fine without the need of any reboot or restart.
I hope anyone can find a way to fix this. For now I will leave the smartmeter “Thing” disabled.