Totally bizarre wifi issue

I have been plagued by a really weird wifi issue on my Dell XPS 9570 for ages now.

My computer can "see" wifi networks.

However, most of the time when I connect to one, it stays connected for 30-90 seconds (and maybe even functions), before disconnecting and stating there are no wifi networks to be found.

This response is triggered by most (but not all!) wifi networks. It won't show any networks unless I restart my computer.

Some networks, such as hotspotting from my phone are fine!

But this issue occurs with 90+% of wifi networks.

At the moment, I am using a usb ethernet adapter at home. Which obviously defeats the point of buying at 2000 pound laptop a few years ago! 

Solutions I have tried:

• Reinstalling drivers

• Updating windows

• Clean install of windows

• Using a USB wifi adapter (admittedly a very old one - from about 10 years ago when I built a desktop and forgot to order a wifi card).

No bueno!

Does anyone have any clues on what I can do to make my wifi work again?