@Nozzer 

Hi pal, 

I am also on bt, using ax72 and I get full speeds over WiFi,

I'm using a s22 ultra, if you can open your Web browser I'm pretty sure you should be able to see what your link speed is Maybe there will be able to see if your only getting a low link speed as that will indicate what speeds you'll be able to get. 

Not sure if the tether app is same for yourself in the tether app but In your wireless settings I have a advanced part , in there you should be able to change the channel width. If its not set to the 160mhz option that could be the culprit as when I didn't have the 160mhz option selected best I could get was maxing out at 700.  

Failing that when I do speed tests say using ookla, 

Not all the servers will run at the full speeds, I think I've found about 3 from the long list it gives you that actually will speed test upto a GB, 

I've done loads of tests where I'll consistently get the gb speeds using mainly trooli server (upto 940/110) and then ill try other servers and get get anywhere between 400-600. Maybe that is where the issue is? 

  @Nozzer 

No worries pal glad the suggestion helped. 👍🏻