WoW flooding and crashing my internet?

I am not tech savvy so i’ll try my best to explain.

I have two accounts, this issue is only affecting one. This issue only occurs through my wifi connection not mobile hotspot.

Throughout today WoW would get stuck on load screens, switching servers and connecting from the battlenet launcher. Initally started as a character load screen getting stuck entering dungeon. I have not been able to log onto that character since. I have tried the unstck character help and it hasnt worked.

After failed attempts to connect/load etc. my internet is unstable. Browser won’t load webpages, streaming quality goes down. This affects all devices (i.e. my family streaming netflix on their phone). Ping timed out on battlenet and my service provider but all else ok.

When i try to reset the interface the game gets stuck on a black load screen and freezes up. If i leave it long enough the cineamatic runs and then infinite ‘connecting’ screen.

I have tried resetting router, resetting interface, flushing DNS, disabling add ons. Nothing worked so far. The only thing that helps is waiting but then the issue appears again randomly after some time i.e. i could be playing one or two toons fine then switch to another and it randomly starts having problems.

To recap, only affecting my main account when using wifi. Other account on wifi or my main using hotspot i have no issues. Only affecting some characters but may be infectious…started with one that i cant get back into and several others have the same starting symptoms appearin now.

Please help!!