Cm11a errors and dimming problems

I’m having problems with the cm11a binding which I think may be related to controlling dimmable devices. On off devices seem to generally work well but I often see errors logged when setting levels on dimmables. Common log entries include:
[.binding.cm11a.internal.X10Interface] - Received EOF exception while sending X10 command after 4010 ms. Make sure the cm11a is connected to the serial port
[.binding.cm11a.internal.X10Interface] - Unexpected data received from X10 interface: 55

In addition, dimming commands are very unreliable, often resulting in no change. Perhaps this is related to the errors such as above. Any ideas how to diagnose this? This is running on a RPi using OH2.2

I’ve been wondering about this too, but haven’t gotten around to posting.