This is for version 1.13.2, for some reason, it will not let me select or type in 1.13

If you build a column upwards to see your surroundings and then start to mine back down, the game moves you off center and you will eventually fall if you do not re-center yourself.  You can mine down a few blocks, but then the game shifts you off center and if you keep mining down, you will fall off of your column.  1.12 and older versions  we did not experience this.