Running Xcode 12.5.1 Causing Cracking Speaker/Headphone Sound - MacBook Pro (15-inch, 2018)

Here is what happens.

I open Xcode and create a new iOS project.

While Xcode is open, I then open safari and play a video on YouTube and get crackling sounds.

I know that if you're running a simulator, you can go into the simulators I/O settings and change the output; however I'm not running a simulator.

My guess is that Xcode runs some built-in simulator for it's "Preview" of Swift UI code.

This is a bit of an issue as I knew the fix for the simulator but how can you stop the crackling sounds from Xcode without a simulator or preview pane open in it?

Only fix I can see is to close Xcode, watch / listen to the video than open Xcode to code...

Any ideas?