Why have 2 routers? Ditch the ISP one, and just use your “good” one.

Try "forgetting *the network.

https://support.my.uq.edu.au/app/answers/detail/a_id/2509/~/how-do-i-remove-or-forget-a-wifi-network%3F

We use NSM devices extensively throughout the Far North Queensland Wet Tropics Rainforest, with monsoonal rains, 38c plus temperatures with high humidity and they don’t miss a beat.

The biggest problem we have is that the trees grow in to their transmission path and need pruning.

Draytek devices have a thing called VPN Matcher. It can allow you to vpn in to device behind a cgnat connection.

Either NextDNS or ControlD would make you job sooooo much easier, and both use adguard lists in some way.

No messing about with VM, no security worries, no maintenance. Can have multiple profiles for all members of the family, works on ay devices you can think of.

We need a sticky in this sub saying “Don’t run copper between building, use fibre or PtP Wi-Fi links.”

/u/liquidburn34 Copper between buildings is a bad idea, more so if you bury it.

Use fibre, it costs the same, it has none of the risks copper has, and is faster.