pve8.4.1

Hello, I have a question. I have a cluster of 4 nodes with 8.4 and I am adding 2 more nodes, but I wanted to take advantage of this to switch to Proxmox 9. Is this possible? Or are there any restrictions or limitations? Best regards

Some details Every few days (at least once a week) the pvestatd service crashes. I can still log in via the Proxmox GUI (and via ssh), but the containers are all displayed with a "?" As soon as I restart the pvestadt service (which also works from the GUI), I can see the status of all CT/VMs...