As a rule on any airline to the DR you cannot check in online. Only when you leave, so nothing new on that front. When you check in they may ask for it or maybe not. Depends on the airline. But checking in the system I doubt that would be normal at all............
I have flown 3 times since August. Along with that, I have arranged 4 family flights. Every one of them, I have been able to check in online and print boarding passes...no problem. With Air Transat, Westjet, Copa, Flair and Arajet, the online check-in was a breeze.
In the past, I could not do that.