I had 3 M5s set up in the house and I recently bought another one. At first, setting it up was a pain. I finally set it up right beside the main M5 and it seemed to work, it went green. I brought it back to where I was planning to set it up, and it would seemingly randomly decide to work or not. Sometimes it would turn green, but say it was offline on the app. Other times it would stay pulsing red. I was able to connect it to my PC with an ethernet cable, but when I ran speed tests it was less than 1 mbps or just wouldn't connect at all. 

After a bunch of factory resets and firmware updates, I can only ever get the light to go green if I plug it directly into another M5. I even made it the main M5 for a bit, and the whole network wouldn't work unless I linked it to a satellite M5 with an ethernet cable. And all the other satellites would connect to the plugged satellite instead of the main. 

Currently, when I try to add it again to the network from the app, it gets discovered and I'm able to go through the process. It says it was successfully added, but the LED stays stuck in a solid blue state and stays offline on the app (unless I plug it in).

Honestly, I think whatever wireless hardware this M5 has is broken, but do you guys think I can do anything else? 

I'm from the Philippines and my ISP is PLDT.