Podman: Permission denied for volume on separate disk (cgroup?)

this works:

podman run -it --rm -v /home/myuser/test:/test:z  alpine /bin/sh

this doesn’t: (mind that /mnt/data is a mount point for second drive)

podman run -it --rm -v /mnt/data/test:/test:z  alpine /bin/sh

It fails with the message:

Error: crun: error stat'ing file `/mnt/data/test`: Permission denied: OCI permission denied

The test directory is owned by the user launching the container so I don’t think it’s a straightforward permissions issue nor it’s about SELinux. I suspect cgroup v2 issues but I can’t seem to find a decent guide on how to set up.

Something’s strange.

when I try the same but on my (internal) backup drive, it works. Volume mounts without any permission problems. I don’t know if it’s related but the data drive is ext4 and the backup is xfs.