GPS accuracy plummets under certain conditions.

TLDR: GPS accuracy good alone. Good with Display Link adapter alone. Good with USB C hub alone. Horrible with Display Link adapter plus USB C hub.

I'm at my wit's end. I have HDMI input on my car's head-unit, and I'd love to use my phone to display navigation on its display. I've been (begrudgingly) using a Chromecast to handle this up until recently. This wasn't ideal, as it required that I turn on tethering on my phone to create a host network for my Chromecast, and also required me to go into my phones settings and select the Chromecast for casting.

As unideal as it was, it was working up until about a month ago, when an update to the Chromecast firmware, the phone's software (or both) broke this functionality. You can now only cast from a device that isn't your network. In other words, the tethering work-around no longer works.

I knew that the Pixel didn't support HDMI-output over USB C, but I remembered reading on an early thread that it was possible it could be added by software update. So I searched and found that some people got it working with a Display Link adapter.

I ended up grabbing this Display Link adapter and this USB C hub. Hooked it up, and everything appeared to be working just fine. That is until the first time I attempted to use it for GPS navigation. My phone suddenly had no clue where it was. I remove the USB C hub and connect the adapter directly to my phone the USB C adapter that was included with the pixel, and it works just fine, but obviously then I'm not able to charge my battery.

I've tried other USB C hubs, and I've got the same issue. But if I connect the USB hub alone, and leave the Display Link adapter disconnected, no issues.

I'm getting kind of sick of jumping through hoops for what should be an included feature. I found myself searching Amazon and wondering if a USB GPS unit would be recognized by the Pixel, and that's when I realized I needed an intervention.

Has anyone else noticed any weird GPS accuracy issues when using external devices? Any resolutions?