I'm in my single player survival world.

Lag! So much lag! Even worse in latest snapshot. (Mind you there is a lot of lag though out the 1.14 snapshots). I mined several blocks then I get jumped back and have to re-mine the blocks again. I even get stuck, I try to walk forwards but end up where I started. I killed most of my pigs and all my chickens to see if that would help (the jury is still out on that). I'm also using an iron pickaxe with efficiency IV and unbreaking III, which may not be helping with the lag. I would have recorded the lag but it decided not to work. (really wish I could have gotten it to work) So you(or someone) will have to play for yourself. I'm going back to the previous snap shot.

PS Oh and don't let me mention not being able to jump when you are right next to a block that is one high. But you already now about that.