I feel like this might be a long shot but wanted to see if anyone else was running the tailscale plugin for Opnsense. I have everything set up when my opnsense acts as an exit node. The clients connect up to the exit node just fine but I wanted to redirect traffic to a different gateway instead of my ISP gateway. I tried setting up tailscale net as the source on the tailscale interface to route traffic to a specific gateway but it doesn’t seem to work. It seems like tailscale ignores all of opnsense firewall rules which is a lot different than what I am use to working with the wireguard interface on opnsense.
You need routing rules for this on the exit node. You can’t use the default routes for the machine and expect a virtual device that is already being routed to know where to go.