Problem with international calling since MDM rollout

Hi *,


since I rolled out the new MDM System via DEP / VPP to our standardized IOS devices, one colleague who work international has massive calling problems.

He does not have the ability to receive or make telephone calls. When he conducts national talks (Germany) everything runs smoothly.

He tested the MDM System in Russia and Turkey and both tests failed.

In the compliance guideline, which I deploy to our devices, I allow the data roaming… I'm not aware I locked anything on the MDM...


Has anyone a hint / advice?!