arris modem router acting strange

[raverx3m]

i have arris sbg-6900-ac router with comcast and cant figure out if its a problem with the router or wireless cards in both of my computers
first off the range sucks and anything in my kid's room barely gets stable reception i always get kicked off game servers on pc and ps4 pro as well.
my desktop almost never shows 5g wifi available but sometimes it comes on

my cellphone and laptop works in every room and connects and shows 5g always


i already moved the router closer and closer to his room so now its in dead center of my appartment and still poor connection to both pc and brand new ps4 pro
but my cellphone shows good wifi signal when i put it next to pc

the wireless cards in both pcs are new ish and router is only 3 years old.

 

[PP Mguire]

Apartments have a ton of interference. This would also explain why you're having issues with your mouse dropping out while the wifi has constant connectivity in D2.