I've had both my M9 plus setup and running fine for almost a year now and have been very happy with it.  Both the satellite and Main Deco have been in the same exact spot for this duration.

2 nights ago, the satellite receiver started acting funny.  Internet performance started being poor.  It seemed like devices were not connecting to it and reaching for the main deco.  Now it alternates from being green (with very poor or NO performance) to blinking red. 

When it connects green the app says the health of the deco is fine.  It will be green for a little bit and then go blinking red.  Then back to green.  The main deco has not suffered any performance issues. 

The satellite deco is currently in a detached mother in law suite behind the main house.  Now, if I move the satellite closer to the main deco it seems to stay solid green and work fine.  Why would this happen out of nowhere, if it always worked fine in the one spot it was in? What can I do to fix this?

Very confused - please help.  Thank you!