Thanks for the response Ron.
I have tried using three separate devices, an iPhone XS, iPhone 8, and an iPad Mini 2. These are all on separate iOS versions 16, 10, and 12. I have confirmed that the Bluetooth volume was maxed when I connected all three devices in separate instances.
When I select the Bluetooth mode on my x930BT, the 'static' noise is very much evident even at low volumes. Its only when I max the volume on the HU can I very faintly hear what song is playing. It's very strange, it would've been easier to diagnose if Bluetooth just didn't work at all
Edit: Which car