Connection to OBD device only works first time

I have the app, with the premium subscription and I have managed to link the app to my car through an OBD ble device. This worked great and I could see my battery % on android auto.

Once I had parked the car and then come back to it the app doesn't seem to reconnect to the car. The battery % on android auto is in red with a line through the symbol next to the numbers. I have tried unplugging and replugging the obd device, and also a different OBD device. But I only seem to be able to get the live data the first time I connect to the obd device and then subsequent drives don't connect.