I confirm,
It seems that is not overlayfs problem.
The problem occurs only with glusterfs backed storage (on nfs server).
I tested this internal gluster nfs server, and ganesha nfs server, nfs-kernel-server is not supported by glusterfs.
With nfs-kernel-server and ext4 no any problems. Even readonly mode.
I confirm,
It seems that is not overlayfs problem.
The problem occurs only with glusterfs backed storage (on nfs server).
I tested this internal gluster nfs server, and ganesha nfs server, nfs-kernel-server is not supported by glusterfs.
With nfs-kernel-server and ext4 no any problems. Even readonly mode.