Newly installed Liftmaster 8550. Added a repeater to ensure strong wifi signal in garage. I get four full bars. The app will connect briefly, then suddenly go offline for extended periods, sometime going back on line. Or I have to reprogram it.
Called Chamberlain support and spent 20 mins going through the same procedures I had done myself. When I explained to the support rep that I had done this several times before, he just kind of glossed over it. So naturally after redoing the setup procedure with the rep on the phone, the MYQ app worked, but just like before it went offline within minutes. So I'm back where I started and just wasted time. With all the postings of this and similar problems, I can't believe Chamberlain isn't taking it more seriously.
The problem is that it keeps losing connection. I will do the set up and it will show connected, then a few moments later will say no connection with server. Sometimes it will spontaneously reconnect, only to disconnect a short time later. So the problem is a case of only working intermittently. I have four bars of wifi in my garage, so I suspect it's the 8550 router that has a connectivity issue. And from the posts on this group, it would seem a somewhat prevalent problem.
I think my problem is resolved. I discovered that the extender/repeater I installed to strengthen the signal in my garage was defaulting to connect with another repeater elsewhere in the house. I believe this caused the opener to see a strong wifi signal, but the internet connection was marginal. At least that is my theory, because after I forced a change to connect directly with my main router the connection is now pretty reliable. I occasionally get a "no connection" message, but it doesn't last long. So I'm pretty happy now.