I came across this problem.
There is a host with proxmox 8 installed. I created a virtual machine with the DNS role. If I try to connect to this machine via port 53 from a physical machine on this network, I get a connection error. If I connect to this machine from another virtual machine (on this host) or from the proxmox host on port 53, then the connection goes through. Please tell me in what area to look for the problem? It is worth noting that there are no such problems with other ports; I installed Nginx and was able to connect to it from anywhere.