Withers glitch downwards while pressing against blocks
When a Wither is in pursuit of a player or mob, and there are blocks in the way, it slowly float down to the floor despite not actually moving.
Steps to Reproduce:
1. Make a new Creative world.
2. Construct a Nether Portal and enter it.
3. Find a low ceiling similar to the ones in the pictures below.
4. Spawn a pig in the back part of the overhang.
5. Spawn a Wither where it will not blow up the overhang.
6. When the Wither starts flying against the blocks of the low ceiling (another bug reported in MC-8630), it will begin to sink towards the floor. If you attempt to hit the Wither when it is on the floor, it will not work.
Linked Issues
Created Issue:
Withers glitch downwards whilst pressing against blocks
When a Wither is in pursuit of a player or mob, and there are blocks in the way, it slowly float down to the floor despite not actually moving.
Steps to Reproduce:
1. Make a new Creative world.
2. Construct a Nether Portal and enter it.
3. Find a low ceiling similar to the ones in the pictures below.
4. Spawn a pig in the back part of the overhang.
5. Spawn a Wither where it will not blow up the overhang.
6. When the Wither starts flying against the blocks of the low ceiling (another bug reported inMC-8630), it will begin to sink towards the floor. If you attempt to hit the Wither when it is on the floor, it will not work.
duplicates
Withers glitch downwards whilstpressing against blocksWithers glitch downwards while pressing against blocks
Ah ok. I wasn't sure if it was related to anything else.
Blazes and Withers will often appear in a spot that they are not whilst flying.
Steps to Reproduce:
1. Make a new Creative world.
2. Spawn a Blaze and hit it.
3. Fly upwards a few blocks and observe it as it hovers upwards.
4. As the Blaze is hovering, notice how it bobs up and down when going back to the ground or just hovering in place.
5. For Withers, refer to MC-9242.




Resolving as duplicate of
MC-7489as this a client-server desynchronization.