4x4 jumps out of gear while driving. why

Hello, This should be an electronically shifted transfer case, so it may be possible that the gears are not fully engaging, but wear is also possible. Bearing or shaft wear allows play, and that generates an angle between the two shafts. The gears sort of walk away from each other. I would ensure there is not a problem with the switch, control module, or circuit before assuming physical damage.