There is simply no lounge access for AM in YUL, I was told a few years ago.

The AF lounge opening hour does not match the AM's flight time either, there's one flight in the morning where AF lounge is closed, and another flight departs at midnight where the check-in opens at 9 pm and the latest AF flight departs at 10:15 pm. I believe their lounge closes at 9:30 unless AF flight delays. Also, AF349 only operates on 1,3,4,5,7 so on Tuesday and Saturday, the AF lounge closes at 7:30 as AF347 is the last flight out of YUL.

The problem here is that AM never subcontracts a lounge in YUL. In YYZ, they have an agreement with Plaze Premium, as the KL lounge is NOT open either at the time AM's flight departs (9 am or 1 am).

AM does not have a lounge in HAV either if I remember that correctly. It's a problem of AM not having a contract lounge in certain airport, other than AF/KL not accepting AM's passengers...

PS: AM does not provide a decent service, old aircraft out of Canada, no lounge of YUL, terrible immigration lines in MEX, and the price is not as competitive as CM to most of South America. I've avoided them for quite a while...