make sure your iphone didn't copy over the old settings for bluetooth devices
if so, delete the device from the bluetooth settings
delete then reinstall the app, unless there is stored data you must save
try re-pairing
for something like that i would use an old iphone in airplane mode ( no sim), that's what I use for the obdfusion app I use to monitor the motor and tranny
there are potential security issues where an app like that may be reporting your location, what speed you drive, when you are awake or asleep, the other apps on your phone and how you use hem- thousands of data points may be transmitted
which may allow 3rd or 4th parties more info that you'd want
https://www.washingtonpost.com/techn...hone-tracking/
Mike