Podman container not accessibe from external IP when started by root

I’ve recently been messing around with virtualisation.oci-containers to get a game server running via a podman container (specifically tiltedphoques/st-reborn-server:latest) and was wondering why I couldn’t establish connections to it via the server’s external IP, but I’ve finally tracked the problem down and I just don’t understand what could cause it.
Starting the podman container manually as my normal unpriviledged user via podman run -p "<my-ip-address>:10578:10578/udp" tiltedphoques/st-reborn-server:latest works perfectly and I can establish connections via <my-ip-address> on the specified port and protocol without any issue.
But as soon as I prepend sudo to my command to make it run via root (as is the case when the container is started via virtualisation.oci-containers, I assume?), the container starts up as it did before but external connections just don’t get registered at all.
My issue seems to be the same one as described here (or at least has the same “symptoms”), but the suggested fix in the linked issues there (loading the br_netfilter module) has no effect for me at all.
I never messed around with the server’s networking configuration besides adding a static IP address via networking.interfaces.<name>.ipv6.addresses (the IP address I added is the IP I want to connect to), so I’m surprised to have this issue when it doesn’t seem to have come up before as I can tell.
I’m not very experienced with networking, and I’m unsure as to what info I could provide to make troubleshooting this issue easier, but if anyone needs additional information to make more educated guesses, feel free to ask.
Any ideas what could be going wrong here?

Additional Info:

  • All my packages are from the nixos-unsable channel
  • nix-info -m:
    • system: "x86_64-linux"
    • host os: Linux 5.15.67, NixOS, 22.11 (Raccoon), 22.11.20220912.5f326e2
    • multi-user?: yes
    • sandbox: yes
    • version: nix-env (Nix) 2.11.0
    • nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos