Did some tests:
1. SIM from SG5 moved to SG3 - MB connected, read phone book, registered in TMobile, dialed in/out
2. SIM from SG3 moved to SG5 - MB connected, read phone book, registered in TMobile, dialed in/out
3. removed Exchange account and all rules (PIN request, PIN lock on the screen) with oryginal SIM my SG5 doesn't work with MB ?
Tomorrow will buy new SIM pre-paid at the same operator and will check.
Difference between SIM from SG3 - not-LTE enabled, no dual-sim service, SIM is from 2012/3
On SIM in SG5 there is LTE (SIM card is from 2014), dual-SIM service enabled (I have two SIM cards with the same number).
Collected logs will send them later..
Discussions about rSAP and general Bluetooth compatibility of the Mercedes-Benz Bluetooth SAP telephone module
Really strange... I still think it's an issue with the card in combination with the S5. Maybe a large batch of cards has these problems, so it may be difficult to get a different card from the same provider.