run this command again
ls -ld /var/log/pveproxy
I think the permissions are wrong here\\
mine looks like this
root@proxmox:~# ls -ld /var/log/pveproxy
drwx------ 2 www-data www-data 4096 Mar 31 03:44 /var/log/pveproxy
root@proxmox:~# ls -l /var/log/pveproxy
total 3224
-rw-r----- 1 www-data...