Can't download container templates

[Ernie Pantuso]

My Proxmox server can't download templates. It gives the error "TASK ERROR: download failed: wget: unable to resolve host address 'mirror.turnkeylinux.org'" but I know the problem is bigger than that because I can't ping 8.8.8.8. When my laptop is connected to VLAN 10, it can't ping 8.8.8.8 either but it can ping my Proxmox server (10.1.10.10) and vice versa. Neither my PVE server nor my laptop (when connected to an untagged VLAN 10 port) can ping the router so this seems like it might be a general networking problem rather than a Proxmox problem but I tried moving it to the main LAN (used only for mgmt nodes) where everything works but PVE still didn't work (so I moved it back to VLAN 10).
I'm hoping someone can help me; I've looked at other threads on this forum and checked/implemented the things that resolved the issue for others but none of it worked for me.

Contents of /etc/network/interfaces

auto lo
iface lo inet loopback

iface enp0s31f6 inet manual

auto vmbr0
iface vmbr0 inet static
        address 10.1.10.10/26
        gateway 10.1.10.1
        bridge-ports enp0s31f6
        bridge-stp off
        bridge-fd 0
        bridge-vlan-aware yes
        bridge-vids 2-4094

Contents of /etc/resolv.conf:

h home.arpa
nameserver 1.1.1.3
nameserver 9.9.9.9
nameserver 8.8.8.8

The server is on VLAN 10 (10.1.10.0). I recently installed pfBlockerNG in pfSense (but this server never worked before that).
I disabled the rule that pfBlocker put at the top. Now the only rule for VLAN 10 is a pass * * * * rule.
I checked the configuration on my switch and I think it's OK - though I'm not sure if an untagged port needs to have the PVID set. (I do have it set.)