Found a member from a previous thread about this issue and that’s what is happening.I’m almost always using CarPlay so?? Lol who knows. I’ll try without tomorrow.
When iPhone plugged into Jeep;
GPS even simple speed apps do 100% match what Jeeps speedometer says.
However and unfortunately it is not correcting speedometer. Instead and who knows why the Jeep is sending data to phone and changing speed readings.
The reality is just about as bonkers as what I had initially hoped for just not as useful.
I even tested it today; Set cruise in 5th gear at 55 while hooked to CarPlay with speedometer ap opened. Disconnected lightning cable and app immediately went from 55 to 58!
Wonder if this is just an iOS peculiarity or of android based devices do this too.
Anyhow mystery solved: I still think my Jeep is magical though.