When either of these two conditions occur:

1. When a player jumps to get out of their mines using a staircase, or
2. When a player is raiding an end city and the Shulker levitates the player

The player starts to glitch into the block above it and starts getting the same effects as they would with gravel, like suffocation. For me this made raiding end cities very hard and annoying. Now I have to make lots of adjustments to my mine.

I only tested this on old 1.16 worlds and I am now getting these bugs when I transferred them into 1.17.