WAN link keeps dying on 21.02 Brume (GL-MV1000)

Hi, I've been unable to get a solid network connection after installing 21.02 on my Brume (GL-MV1000)

I turned off ipv6, deleted the ipv6 wan interface and changed the mac addresses of the wan and lan ports. I'm IPV4 only and don't want the ipv6 services running. No other changes as far as I know but the WAN port keeps dropping constantly and I see it in the logs. Anyone else have this issue? Can I fix this? The official firmware based on an older version of openwrt works perfectly so I know it's not a hardware issue.

Just tested it again. I reflashed the 21.02 openwrt file via uboot and left the defaults and hooked another router into the brumes wan port(instead of my modem, testing it offline) and I'm seeing the same exact thing. constant random drops where the wan port goes up and down. The LAN side seems to not have any problems as far as I can see. It's only the wan port dropping and killing the incoming connection.