7.23.1 Resolvable route is unreachable. Did I find a bug or doing something wrong?

[CGGXANNX]

@divB

Now I want to do the opposite as well: DNS is part of main VRF but should also be available from vlan55 (which is part of vrf-as):

/ip route
add distance=1 dst-address=10.2.79.2/32 gateway=172.18.1.20 routing-table=vrf-as scope=30 target-scope=10

Here 10.2.79.2 is RouterOS's own IP in main VRF. Note that above route command is identical to the one above (just IP flipped).

However, this route shows up as Unreachable!

The reason why this route is unreachable is because you forgot to include @vrf-as at the end of the gateway. It should be gateway=172.18.1.20@vrf-as.