This bug has existed for over a year and only seems to be getting worse.
When building upwards in a single block tower, eventually (especially when going fast) the game will experience what is presumably a lag. It thinks you are one block lower than you visually are and since there has already been a block placed in that spot, you are pushed to the side, causing you to fall.
Steps To Reproduce:
- Take full blocks in hand
- Jump up and place blocks right under player, building upwards
After a while (faster when building up quickly) you will be pushed to the side, off the built tower.
Building upwards causes no issues of falling when not moving in any direction but up/down (jumping).
This happens less when taking a short break after each jump, but this makes the process significantly slower and does not fully prevent the issue.
Experienced this issue since 1.17, possibly earlier.