I've been having a problem for the past few months with game controllers cutting in and out, BT and USB, with any controller I'm using.
I've swapped to a new PSU (850W Thermaltake GF1), swapped my power strip for another, and even connected my BT adapter to a powered USB strip, and it still happens.
Three things that stand out:
1) This started happening shortly after I got a new 970 EVO Plus, moving my old 960 EVO to the second M.2 slot, and reinstalling Windows. I'm not sure if it's somehow causing these issues or not
2) Lately, I occasionally see the lights flicker. I don't know if it means I have too much draw going on. I have a surge strip with 8 things plugged into an outlet, and a separate outlet with 4 things plugged in which may all be on the same circuit. However it feels like if that was a problem, I'd be noticing more of an issue in with crashes in gaming and worse than just USB. The room has two 20A circuits, and even if everything I have in this room is on the same circuit, it feels like I shouldn't have a problem with it (PC, two monitors, modem and router, TV and soundbar, cable box, PS5, Switch, laptop, and printer.).
3) At first, rebooting seemed to help the issue, but today, that didn't help much.
The next thing I can think of to do is to replace the motherboard, but if I do that, I may end up replacing the processor. As nice as a component refresh would be, it would be irritating if I did so and still had the problem. I'm also considering a UPS in case there are any brownouts that aren't making my system otherwise unstable.
Current specs are:
Core i7 8700K
ASRock Z370 Gaming K6 motherboard BIOS 4.20 (current)
2x16 Team Dark RAM
1 TB 970 EVO Plus boot drive
eVGA GTX 1070 (Superclocked, I believe)
Thermaltake 850W GF1 PSU
Windows 10 Pro
Any help would be appreciated.