OK, I figured this out. The problem is that East Bank Station exists (as a railway platorm), but West Bank Station doesn't exist. West Bank (sans "Platform") does exist however.

I think this is a problem with the deduplication that the autocomplete does. When the geocoding server returns a bunch of places near each other, the autocomplete just shows the first one. That’s usually helpful, but in this case, it seems to be junking the station in favour of an actual bank! I’ll see if I can tweak it a little.