I have the exact same problem. I'm using LVM on ISCSI (shared)
root@proxmox1:~# qm rescan
root@proxmox1:~# pvesh get /nodes/proxmox2/qemu/100/status/current
{
"cpu" : 0,
"cpus" : 1,
"disk" : 0,
"diskread" : 208896,
"diskwrite" : 163840,
"ha" : 0,
"maxdisk" ...