This issue to my knowledge has never been resolved. My got rectified after i had to replace the M1XEP board after a lighting strike. With the new board in place the issue went away. I believe what has been happening is that the XEP board never really gets updated correctly or the interface to it never really gets good communication after an update.
If anyone still haven’t resolved this issue, try starting RP as ‘administrator’ at least once. Requires the one time then future RP start can be normal (without the need administrator rights). Seems to fix it for me.