Yes, that’s how it works.
The IP used for checking is bound to the interface for the check, and as such is NOT reachable if that interface is down. It should not be used as an available resource!
Here a little story : http://forum.mikrotik.com/t/can-somebody-explain-scope-and-target-scope/41190/1
There are enough IP addresses that can be used for checking (only) and still have that function from elsewhere. https://www.lifewire.com/free-and-public-dns-servers-2626062
Some also set multiple check-IP’s for the same recursive route (see #130)