@ZedKuro 

Hi,

In case your Archer T4U Plus has the letters "EU" printed on a small label on its bottom side, then it doesn't support the channel numbers 149 to 165. 
However, 5 GHz hotspots of smartphones do quite often use exactly those channels.

If you have some other Wi-Fi device available that can connect to the iPhone's hotspot, then you could use that device to confirm the channel number that is used by the hotspot.
 

  @woozle  i just checked on my laptop and yes its indeed network channel 149.. what can I do? its the only source of good wifi I can use can I somehow change the channel of my phone hotspot or anything? P.S it does say EU on the label... can you please help? 

  @ZedKuro 

This kind of problem has been annoying many people already.

According to what other users write on the Internet, the iPhone does not allow manual selection of the channel. (and the same is actually also true for most other modern smartphones)

So, the only way to solve this would be to use a Wi-Fi adapter that supports all channels.
 

  @ZedKuro could you recommend me a wifi adapter that does support all channels? also I remember once trying things with my IT friend and we managed to get it to work on 5ghz and the next day when i booted up my pc it didnt work..

  @ZedKuro 

If your IT friend knows a repeatable trick to make it work, then surely many people here would like to hear about it. 

But it is also possible that on that day your iPhone just decided to use a channel other than 149, one that the Archer T4U Plus "EU" can actually see.

Normally I would not recommend products of other manufacturers here, but given the circumstance that probably all the TP-Link products you can buy at your location are "EU" models that can't work with channels 149 and above, I will tell you that any generic (no big brand name) Dual-Band USB Wi-Fi dongle I've got directly from China has worked fine for me on all 5 GHz channels.

  @woozle thank you, now I just need to save up money for another one.. and tbh i dont know my IT friend was just testing things and it somehow worked and the next day when trying to make it work again it didn't work at all so probably a one time thing of the iphone not being 149 channel.