I did Install OMV6 6.0-17 (Shaitan) on a separate hardware:
By the way, very nice UI improvements !
No docker app running except Portainer.
I have let the system running (idle) for a few days and I noticed that the used memory in the Dashboard move from 5% to 10% in 1 week. (I have 16 GiB)
Let me know if there are logs or other that will/could help narrow down the issue (if any)