We did apply a retention policy. Both are offline now for almost week.
I still get the message:
"Site can not be deleted
A compliance policy is currently preventing this site from being removed"
The only place i know i set a retention policy is in O365-> Security & Compliance.
What are we missing?
Contacted MS helpdesk.
First action for them was to start company Sync from background, this would take 24h to complete.