I'm in such a similar spot:
Starting my G6 - NIGHTMARE!
Well, that's a day of my life i won't get back again.
I put on my G6 Sensor and Transmitter, then i told xDrip+ to start the sensor.
I used the Source Wizard Button to choose the G5/G6 sensor.
At first it "seemed" like everything was ok.
...
I started a G6 sensor with 8H transmitter using Xdrip on Android 10. I'm done with the 2 hours wait and rather than getting readings, I see: "G6 State isn't currently known. Next connection will update this." But it's been over 15 mins since the clock ran out to zero and I don't think that there will be any "next connection". In the Xdrip events log, I see no evidence that there is any bluetooth chatter between the phone and transmitter, except for the lone entry from two hours ago "DexTimeKeeper No valid timestamp stored for transmitter). There simply aren't any events or errors indicating that the phone is attempting to talk to the transmitter at all.
I guess I will try the Dexcom App, which is a real bear since I want to use the Xdrip alarms and auto send my data to tidepool. I suppose I could collect with the dexcom app and then shoot everything over to xdrip, what a mess.
You said that you were able to restart the sensor using the Dexcom app, but how? I have used Xdrip to restart a 8g sensor by physically disconnecting the transmitter, and waiting the 2 hours, but the readings afterwards were *****. Were you able to get around the approximate 15 point increase after restarting?
UPDATE: Dexcom App won't work! Says my device is incompatible. I have a Pixel 3AXL running Android 10. The official list of compatible phones lists Pixel 3XL, not Pixel 3AXL.
So now I'm wearing about 350$ of junk.