iOS update problem / interrupted

Hello,

we have problem updating apple devices.
It does not matter if we update with actions -> available updates -> install update or if we use the policy to update.
In both cases, the devices start to update, but the updated gets interrupted and abort.
If we use the update function on the device itself over the settings menu, the update works just fine.

Is there anybody who faced the same problem or may know a solution for that problem?

Thanks!