Sensor value updates frozen

[gavwhi]

I've found that every few hours the sensor value updates become frozen. For example, my non-Essential vaule hasn't been updated for 17 minutes now. Restarting the add-on fixes the issue and everything starts to update again. In the logs I see lots of errors similar to this:

12:16:03 ERROR OSError in callback read_ss: AttributeError reading 8 registers from 0: 'Serial' object has no attribute 'host';

I have a Sunsynk 5.5 ECCO using a wired RS485 waveshare dongle. Where do I start to troubleshoot this?