Push notifications with gdmss plus stops working after a while

I installed it now on several devices. On none with Android 6 or newer it´s working! Unfortunately I have no response to this problem. Really sad ...
I am sure, its a push redesigning necessary, to meet the new android doze requirements, which has come up with android 6.
 
Does anyone have an issue where it doesn't show snapshots, the push notification comes through fine but it says 'no permission' when it opens the snapshop. The live view feed from the notification works fine as does the playback?
 
Yes I also have this sometimes. Retrying sometimes solve this. But not every time. Maybe there are no snapshots at this event? The messages are often not that what it says, Chinese translation

But I am more sad about the problem with push notification. But I am sure it's only for android 7 and above. Although we received several updates, it's still broken.