Jungle adventure: how to explore all the jungle

It is completely random AFAIK, so my guess is that you have bad luck.

Agree with the random. Sooner or later have made it to all the locations, though some seem to be closed more often than others.

Have never had the baths closed. The most frequentlly closed ones I've encountered are: the airplane, the gardens behind baths, and the far to the right fishing spot.

There is usually one closed for me each time I go to visit it and that's because I don't really bother opening it since I'm just usually aiming for the temples. But yes, they are very random, I think it's mostly to help cut down on boredom when visiting the jungle for multiple vacations.