When walking and running on path blocks the game 'sticks' and causes both a slowdown of movement and glitching of the game; it creates an effect of suddenly slowing down from sprint, then re-engaging for a moment.  The 'stickiness' continues until off the path block.

Likewise, when moving from any block lower than the path block to the path block that should allow smooth movement without jumping, the 'stickiness' occurs but doesn't allow for movement without jumping.