MIka - Exactly my comment - WestJet is flying Sundays - May 13 onward has seats

When you do book, you have to use the drop down menu on the fare choice, the 1st choice is Econo with restrictions and says no seats, but 2nd choice is Econo with added cost options and it has seats - ......
Or just phone WJ, but there are seats on May flights if that is what you want.

However the WJ cost is the highest ever to SXM

J&B