Why is Bluetooth cutting out on multiple devices?

[TREMAiNE]

I mostly work night shifts, so I'm up all night when I am on my days off.
I'm usually either watching TV or playing video games.

If I am playing games, I'll connect my Bluetooth headphones to the TV, and then play games on my PC which is connected to the TV via HDMI.
Whether I use a keyboard/mouse or my Xbox controller, they are connected to the PC through Bluetooth.
I have done this for MONTHS without issue.

Tonight though, I am having a weird problem where Bluetooth cuts out on BOTH the headphones and the controller AT THE SAME TIME.

WHY?

The headphones are connected to the TV.
The controller is connected to the PC.

How can they possibly be cutting out at an identical time?

They should be working independently of each other.
They shouldn't be cutting out at all. It's happened 4-5 times now.

Very frustrating.

Any ideas why this is happening?

[Mr E]

RF interference at a guess.

[Digger]

Have the headphones ever been connected to the PC?

What have you tried re trouble-shooting?

[Haltamer]

Any microwaves, or other weird electrical doohickeys in the vicinity? (RF Interference as above)

Any chance it's the PC lagging / stuttering (Hence loss of input & audio?)