How to get rid of "Send queue is full! The eBUS service will reset the queue to ensure proper operation."

yesterday I installed the bindings on OH2 for eBUS (HW is based on FHEM concept). I browsed through this forum and broader internet but couldn’t find any solution for me.
I set the transport-serial using openhab console as suggested in one post but it doesn’t help. I noticed this appears after some time regardless if HW is connected or not. Also, I can’t make my set parameters working (even though it sets them in the OH and change is properly notified in events.log they get immediately overriden from the binding with previous value). I don’t know if it has anything to do with the above problem but raising it just in case it may be. Any suggestions?