My wife and son are flying MLE-KUL-PNH with a 1hr 50m hour connection. They will have a checked bag. It's on one booking through airasia.com, economy promo rate. One PNR.

I assumed that the bag would be checked through at KUL but now I am worried because I'm reading that AirAsia only does that if you have "fly thru service" and I don't see anything in the booking that says "fly thru service" nor is there any way to add "fly thru" service?

Will they have to go through immigration, collect the bag, etc.? If they have to re-check it, is that done easily in the arrival hall or do they have to take the bag to the departures terminal and line up with other passengers checking in for flights and dropping bags, etc.