[K4sum1]

That didn't change anything, but I looked through the logs, and noticed a couple things. There's a daemon.warn from dnsmasq that says "warning: interface oet1 does not currently exist", and this gets sent twice. I also noticed it errored out checking the time server, but it fell back to direct IP access, and it succeeded. So I disabled the tunnel, and tried connecting to a direct IP address, and it worked. So I think dnsmasq waits to get DNS until interface oet1 exists, but it just stops trying before oet1 exists. Which means just means no DNS.

Not sure how to fix this.

[egc]

Under DNSMasq Additional options add:
server=/your-domain/9.9.9.9

instead of your-domain add the domain name of the WireGuard server

You can check everything with:
grep -iE 'oet|wireguard|dnsmasq|eop' /var/log/messages

I also have this and it works for me so that is normal:
Jan 1 01:00:16.774 EA6900 daemon.warn dnsmasq[1008]: warning: interface oet5 does not currently exist

[K4sum1]

So that got the VPN to work, but something is now majorly broken with WiFi and/or DHCP. After a minute after boot, I stop getting internet on 5GHz, and I very intermittently get internet on 2.4GHz. Syslog is spammed with DHCP related stuff, which I think is WiFi dropping out because the 5GHz signal becomes one bar instead of the 5 it should be. I noticed in the Wireguard guide, DNS Servers via Tunnel is blank, so I decided to try doing that instead, and that also worked, but also gave the same issue. I don't know what's wrong here. I'm going to update firmware and reset nvram and try again I guess.

[egc]

Unfortunately the builds for your router are still a work in progress.
Anyway glad your wireguard problem is solved