I just got a new Mooshimeter, and I also have a Pixel.

It was stuck in the same situation you describe. I updated the firmware several times, but it was still stuck. I even tried a different device (Nexus 9), with the same result.

In the end, I was able to get it working by:

1. closing the app
2. turning off bluetooth
3. popping out and replacing the batteries in the meter
4. waiting 10 seconds for the slow blinking to stop
5. turning on bluetooth
6. restarting the app

At this point, it showed as a meter, not bootloader, and I was able to connect.

I’m not sure which of the steps above actually fixed it, but it seems to be working now.

Hope this helps,

Eric