Me too! My Liftmaster 8550W has been a quiet workhorse mechanically, but the electronics, the myQ app, and the help pages are not very helpful. I had my system set up for a few years with the Chamberlain Home Bridge for HomeKit, but it would sometimes stop working. Last year I removed things and set it back up so the bridge was the only device listed in the app. This worked, but we would sometimes get notifications that the door was left open. Support tried to help, but we got nowhere, and more involved steps were needed. I did not have the time, so I left it as is.
Fast forward to today and I wanted to remove the Home Bridge (for the software HomeBridge) and the unofficial myQ plugin. Why not? I removed my Home Bridge from the myQ app and the bridge from the iOS HomeKit Home app. So far, so good.
Using the iOS myQ app, I asked it to add my garage door as a device. I found my wall control in the list, and the instructions were to choose Program, WiFi Setup. I should hear a beep. I did not hear a beep. This is the start of two hours of debugging.
The app’s “didn’t hear a beep” link took me to instructions to get on a ladder and press the learn button three times. I should see the rectangular “Activity” button (the one between the arrows) glow blue and beep. It never did either. The only thing that happened was that the up arrow button started flashing.
Further link following suggested that I reset the WiFi on my garage door opener. This is done by pressing the rectangular activity button, waiting for a beep, then waiting other six seconds for more beeps. The beeps never came. One of the help pages suggested that this meant my WiFi was never set up, and took me back to square one.
I did notice this: All documentation about the rectangular activity button should either be off, blue, green, or blinking blue or green. It was none of these! The left half was blue, the right have was green.
Well I tried everything. Unplug the garage door opener from power, but it stayed on because of the DC battery backup. I unplugged the battery backup from the other side of the unit. Nothing worked. Resetting WiFi did noting, starting WiFi setup on the door control did nothing, and pressing the round yellow Learn button just caused the up arrow to flash.
Then I found this video on YouTube from America Overhead Doors, LLC. This was the fourth video I had watched, and each video had different things to try, like disabling the 5Ghz radio on my router, but my issue was different. My issue didn’t match anything. The person in the video showed pressing the yellow learn button three times, with one key difference: Press and hold it until the little yellow LED to the left of the Learn button goes out. Do that three times.
The first button press did nothing. The little LED did not come on, and holding the button in did nothing. The next three cycles of pressing and hold the Learn button down until the little LED went out worked, and after three times, the garage door opener beeped three times and reset.
This is a factory reset. This resets WiFi, your remotes, everything. I even noticed that the rectangular Activities button was now completely off, not half blue/half green. Neat!
I grabbed a remote and used the door control to learn it. That was super fast and successful.
Then the real test. I used the door control to choose Program, then Setup WiFi, and the garage door opener beeped! Even better, the myQ app said that it wanted to use my camera to take a picture of the serial number. Ok, great! I got on the stool and took a photo of the serial number, which was on the same side as the buttons. Next, iOS asked if I wanted to join the myQ Wifi network (no hunting in Settings!) so I chose Join. The device was added to myQ, and the WiFi changed back to my home network.
I tested the door with the app and it worked perfectly. I then went to Home and the HomeBridge saw the door and it worked too.
Hours upon hours were wasted because Chamberlain does not document this half blue/half green Activity button state, or at least doesn’t make it easy to find.
Good luck!
Steve