My router resets or loses connection

I have the exact same router and the exact same problem. I went to L2 support and now they want me to go with Engineering support to continue figuring out what is happening. I have roughly 50 or so IOT devices (light switches, cameras, speakers...) and they just cannot connect (or some do, but most don't). And when I reboot the router, I usually cannot connect from the phones in the house. I was sent a replacement router, but it does the exact same thing. I am not sure what I am expected to do, but I will see if I need to talk with the L3 support and figure something out. I have bought another expensive router from a competitor - and it is working flawlessly. Very frustrated and running out of patience.