Adapters can have the same name (usually OBDII) but a different address. The connection is made not by the name of the adapter, but by its address. Therefore, if you have not selected the adapter that is connected to the car’s connector, the program will not be able to connect to it.
Solution: Go to Settings -> Adapter -> tap the “Device Name” field to select the device and select the correct ELM327 adapter there.
To eliminate possible confusion, I recommend removing all unnecessary adapters from Android settings.