The easiest solution is to just use a USB Bluetooth dongle and not using the built in one. You can get one that's Bluetooth and Wi-Fi together solving both issues.
Are there any types you could recommend? I managed to dig up one among some older stuff (my guess is that it is maybe 5-7 years old), but it performed significantly worse. It is a small dongle (like a USB Receiver) and I am sure it was quite cheap.
Hm, yeah, I am connected on 5 GHz on all my devices and it is working fine. My main VLAN runs a combination of 2.4+5 GHz.
I have some light bulbs that use Zigbee which would be the only other things running on 2.4 GHz in my home. Could it be a source of congestion, and if so, why did this not happen with the previous computer?
I checked out WiFi Analyzer. What exactly would I be looking for here?
Which channels are clearer, etc. It's not my app so I'm not an expert with it, sorry. I just know you can get lots of data with it.. maybe too much. It might help to identify if there's a device that's transmitting with way too much power and messing up other things, especially if those other things (your little computer) aren't able to work around it for some reason.
Microwaves make 2.4ghz interference if they leak also, but you probably don't have one running all the time.