Hi @AntonD ,
After reading this post I could answer that the swap file is not neccessary.
‘New system - SWAP size for suspend to RAM - #4 by Aragorn’
What are the ouputs of the following terminal commands?
cat /sys/power/state
cat /sys/power/mem_sleep
cat /sys/power/disk
I can not explain this line from the journalctl command you posted.
change: deactivating -> disconnected (reason 'sleeping', managed-type: 'full')
It seems something related to the Power managment.
Please, take a look at this post:
‘Power management/Suspend and hibernate - ArchWiki’
Hope it help,
Regards