Raspberry Pi 3 - Weird Network Issue

Hi

Here is a weird thing I can't figure out. I am stuck with Vodafone broadband and their router. Unbelievably Vodafone thought it would be a good idea to stop you from changing the WiFi channels in the router settings... This rendered some of my 2.4ghz devices completely useless as it would usually auto assign a channel above 13... My raspberry pi3 is 2.4ghz built in WiFi so it only worked if I was lucky enough to get a low channel auto assigned.

It seemed simple enough to fix just get a 5ghz USB WiFi dongle right? Yep worked a treat at first for months however and this really random after 24 hours it won't find the WiFi on the Pi unless I do a DOUBLE router reset and this is EVERY time???

All my other devices work fine and the Pi picks up every other router every time all the neighbours routers and my phone as a WiFi hot-spot. I just don't get why it needs a double reset can anyone explain what is happening?

Thanks