XRS1398: Unable to insert 'unknown' into session.

Hello,

I have a problem with some android devices when I push an Android enterprise Application.

I am pushing the App to 30 devices in a group, unfortunately only half of the devices get the notification for installing.

If I select the other half and push it again, also not all devices get the notification...

In the Afaria log I saw the following Error:

XRS1398: Unable to insert 'unknown' into session. EXPLANATION: The channel/set (original channel id = -20, original server id = vof7$e) was not found and will be removed from the queue. ACTIONS: None.

I also saw the KBA for truncating the Database Table "A_CLIENT_NOTIFY_CHANNEL_Q" but this doesnt help.

All the devices are Samsung Galaxy S7 and have the Samsung client "MMEP" installed, and the Afaria version is Afaria 7 SP013.

Is this a Bandwith problem? The App is about 21 MB in size.

Thanks and best regards

Michael