Pairing Karoo2 with smartphone

I had the problem that I kept losing the pairing with my mobile phone when I shut down the Karoo2 (without a SIM card) and restarted it later. I had to keep reconnecting. Many, many attempts without success.
Then I had the idea of deleting my Karoo app on the mobile phone and pairing my Karoo2 with a friend's mobile phone.
This was successful and the connection was maintained. Everything back and connected to my mobile phone and since then everything has been as it should be. The coupling is retained after each restart of the Karoo2 and no longer needs to be called up on the mobile phone.

Norbert