Hi,
After rebooting a whole cluster (node by node), it is impossible to access the PBS.
Everything is up to date.
Sep 23 10:31:04 dc-prox-09 pveproxy[68324]: Clearing outdated entries from certificate cache
Sep 23 10:31:06 dc-prox-09 pveproxy[68323]: proxy detected vanished client connection
Sep 23 10:31:06 dc-prox-09 pveproxy[68323]: worker exit
Sep 23 10:31:08 dc-prox-09 pveproxy[44722]: proxy detected vanished client connection
Sep 23 10:31:10 dc-prox-09 pveproxy[44722]: proxy detected vanished client connection
Sep 23 10:31:10 dc-prox-09 pveproxy[49695]: proxy detected vanished client connection
Sep 23 10:31:26 dc-prox-09 pvestatd[2161]: status update time (37.271 seconds)
Sep 23 10:31:38 dc-prox-09 pvestatd[2161]: status update time (12.307 seconds)
Also, it is impossible via the GUI to browse other storages like Ceph, NFS, etc...
After removing the PBS everything works as expected.