When playing in split screen co-op there is a weird glitch where the whole floor on in the mines won't let you pick anything up, and the animations freeze. Leaving the mines or going to the next floor fixes the issue.
This happens to my gf and me as well, on Xbox. Sometimes once a day if we are spending a lot of time in the mines. She (host) sees the animations freeze, my screen doesn’t show that but I also can’t pick up any items or do anything besides break rocks and use the ladder.