WiFi cuts in and out when bluetooth is on, works fine when bluetooth is off

On my 6P, the flow of data on WiFi stops every few minutes, remains out for 10-30 seconds, then comes back. Usually, it will fail over to LTE data automatically. Then after 30 seconds or so, reconnects to WiFi. *THIS 100% ONLY HAPPENS WHEN BLUETOOTH IS TURNED ON. * If I turn Bluetooth off, WiFi remains on rock solid.

I don't know if it's related or not, but the only time I can get it to use WiFi for calls/sms is if I put it in airplane mode so it had no choice to use WiFi. It will never switch to or utilize WiFi calling automatically. The 3G signal in my house is nearly non existent, so it should be using WiFi in nearly all cases.

I use Pure Nexus. Updating to the latest version 2 weeks ago made no difference.

I have already been down all the roads with routers, WiFi channels, DHCP, and any other fix that could possibly be unrelated to the 6P. It's none of them. Again, this only happens with bluetooth turned on, and does not happen with bluetooth turned off.

Any suggestions? 

Gear fit 2 bluetooth audio cuts out

So i got the gear fit 2, and I like it. My main issue is that the bluetooth cuts when streaming music directly from it to my bluetooth headphones. I returned the fit and got another one and the new one does the same. I tried 2 different bluetooth headphones and it does the same with both. Both headphones work fine when streaming from my phone, so I think it's an issue with the gear fits in general. Any suggestions?

Reception cuts out

Can someone help me figure this out...

Whenever I install a new Stock ROM (eg. v20E, v20F, v20H etc) on my LG G4 H815 I seem to have a problem, where after rebooting the handset (or even after turning it off then on) I type in my SIM PIN code, the phone switches on fine but 10 seconds after that my reception cuts off for about 30-40 seconds, then comes back on.

NOTHING else is visibily affected, everything else seems fine.

The ONLY exception is my ORIGINAL stock ROM (H81520D_00_0115.kdz). The reception cut off bug(?) isn't there.

Is there anything I can do to stop this. I am currntly using H81520d_00_0620.kdz and even this ROM has the issue. I'd like to stick to it as it has the latest security patch, but its annoying every time I reboot, I can't make calls or send SMS straight away.