How do i trigger CARP on LAN? When having P2P WAN connection?

[professor]

I have this situation.

We have 2 pfsense bokses in HA. Both of these have a fibercable connected, Which is the uplink connected to BGP. Both of these have a Point-to-point connection, 10.225.0.172/31, and 10.225.172.174/31, and BGP running on top of that. I cannot create a CARP on these connections. The problem is that i cannot get pfsense to montior the 10.225.0.172 address, even if i add it as a fake gateway, and add the IP to monitor, it does nothing then the link goes down.

And this is even after marking the other WAN(only for pfsense internett) as always up, and changing the fakegateway to default.

So how do i trigger CARP on LAN, when 10.225.0.172 stops answering ping?