Hello everyone.
I have such a problem. On proxmox openwrt works as a dhcp. All virtual machines launched on proxmox are in the network, but proxmox itself does not receive an IP...
It looks like you did not configure /etc/network/interfaces for DHCP in order to get an IP for Proxmox via DHCP. Also, Proxmox does not come with a DHCP client out of the box (unless I''m mistaken) and it does not refresh it's IP via DHCP unless you configure it to do so. There is also a whole sub-forum about networking: https://forum.proxmox.com/forums/proxmox-ve-networking-and-firewall.17/