The Air Canada/Aeroplan website does not recognize a valid IATA airport code for an airport served by a Star Alliance partner. Anyone seen this before? Any recourse?

Admittedly, it's a fairly obscure airport (probably to most of us): NOS - Fascene Airport in Nosy Be, Madagascar. But it's served by daily international flights from Ethiopian Airlines (a Star Alliance partner, and by most measures the largest airline in Africa). The IATA code is NOS, I've also tried the ICAO code (FMNN) with no luck. The airport ID *IS* recognized in a search using some (not all) other Star Alliance partner websites - notably, it's recognized by United, Lufthansa, Swiss, and (of course) Ethiopian. Air Canada's is not the only airline website that fails to recognize it as a valid entry in a search (TAP, ANA, SAS and Turkish do not).

There is some variation in how the location name is spelled in different systems: United's system call it "Nossi-Be", several others call it "Nosy Be" (Lufthansa, Swiss, and Ethiopian...and they fly there). In Air Canada's system, none of those variations are accepted. While probably fairly obscure to most North Americans, it does get international tourists (otherwise Ethiopian wouldn't be flying jets there every day).

Is this (Air Canada's system failing to recognize a valid airport ID) a known issue? Any way around it? Thanks for any insights.