I've had similar things happen to me before because I somehow managed to toggle the "avoid highways" setting without realizing it.
There are no other links, which is why even when you choose “avoid highways”, you still get put on the 99 between Squamish and Whistler, since that’s literally the only road that connects the two. You get put on some alternative backroads between Squamish and Vancouver, which are horrible to use (it was the only option at times while the 99 was being upgraded for the Olympics)
Figuratively. Technically from Whistler you can go north on 99 and then south on 12 and west on 1 and be back at Vancouver.
Plus, that's basically all highways.