Popcorn Entertainment describes Time Trap as follows:
"A group of students venture into the deep caves of remote Texas to locate a favorite archaeology professor who inexplicably has gone missing while searching for the Fountain of Youth. In the course of their pursuit, the group unwittingly rappels into a break in the space-time continuum, where time passes much slower than on the surface. With no hope for rescue, they descend further into the cave and uncover the most coveted urban legend in history and find themselves in the crossfire for its control."
Inverse recommends you see this movie now on Netflix. The best sentence about the recommendation?
"Time Trap doesn't bother explaining its premise, and because of this, it's much easier to buy into sci-fi. Why does time run slower in the cave? It doesn't matter; they just have to get out."