@nebulon seems also that the swap file was commented out in /etc/fstab
(again not sure why/how) so it doesn't persist across restarts, and I guess the script you posted wouldn't affect this.
# /apps.swap none swap sw 0 0
After uncommenting and reboot now
, there seems to be a swap file via swapon
:
/apps.swap file 3.7G 1.8M -2
And all apps are running / stopped as expected, nothing hanging 
thanks for your patience and help 
.
I wonder what about this could have to do with the latest Cloudron update as I didn't touch anything in the last days and everything seemed to be fine.