NC14 android app - instant upload not working!

Hi,

on my NC14 installation everythin ist fine, caldav, carddav, filesync from LINUX and MS desktops. manual sync from my android devices, exept one - instant upload isnt. working.

Samsung S7 and Samsung Tab S2.

I try all 4 apps - Google, f-Droid incl. the latest BETA versions - all of them with no luck.
As well I put them on an brand new wiped phone - no luck!
I could not find anything in my serverlogs. selinux is off as well I shutdown my web applikation firewall.

is there any know issue?

Regards
plepps