PROBLEM!!Extemly low internet speed

Hello i have a verry slow internet connection on my pc using a Wifi adapter ,

the speed is less than 10% of what i am getting on my phone using the same wifi.

History:

Few days ago it was working fine no problems what so ever.

(adapter is brand new)

i had full speed until i hit massive lags in Games .

I changed the QOS to disabeld and the lags where gone.

my speed at this point dropped just a little.

I visited a friend to play some games ... and the stick was with me at his playce my connection was starting to lag.

i didnt mind and went home after the Wlan- party XP

At home...

I didnt notice anything until the speed dropped so hard i couldnt even whatch youtube properly.

this issue is presistant since multiple days.

Things ive tried :

unplugging the adapter, restarting the router, checking rooter settings for my pc( only thing special beeing ports enabled), tried multiple usb ports and ofc restart pc.

i also checked for ongoing downloads in the background.

thanks for help!!

pls ask for any needed info !