can't snapshot with bind mounts

There exist other workarounds:

If you use ZFS, you can simple create snapshots yourself via zfs snapshot. I use this all the time.
 
Yes, you're right, thank you. Unfortunately I have several disks with lots of stuff on that are ext4 so that doesn't help me, but I'm sure the info will be helpful to others.
 
Sorry, I'm not sure I understand the question! the containers are on the NVMe ssd that I installed proxmox on, in whatever the default format is for that. Does that answer your question?
 
I don't think so, the snapshot button is greyed out, and pct snapshot 100 gives me an error (I'm not at home right now so I can't quote it).

edit:

If there is a way, I'd be grateful to know it?