It could happen due to router using frequency that is being abused by others routers. If you live in apartment that is totally true. To switch that frequency you need to login to router administration interface through browser. Login to arris will help you to get though this. Just open your browser, type 192.168.1.1 and you good.

Forgive me as I am far from a tech expert... We “upgraded” from 75 to 100MBPS and also upgraded our router. We have “regular” and 5G wireless networks and everything is now very slow! We have a lot of devices, but didn’t have any issues with the 75MBPS. The wireless also drops on my iPhone all the time and when I try to reconnect it says incorrect password (when I know it’s correct and it will reconnect on its own). What the heck is going on? I use my phone a lot so when it drops off WiFi I blow through my data. Help??