Ok, thank you for your answer
@OcelotOnesie Is it really the same ? No zombies were involved at any point.
It did the same to me but not necessarily when I moved, sometimes the ghast just turned away and then shot instantly as soon as it was facing me again
Bug still present in 1.16 stable release. Ghasts spawning everywhere all the time, 3-4 wither skeletons spawning every minute right in front of me on a single bridge, 5 or 6 skeletons in the same soul sand valley chunk. Blazes are also spawning en masse in and around fortresses without being near any spawner (and therefore rendering the spawners useless)
Yes, they're escaping the pen.
Happens to me all the time, don't even need to quit the game, just exiting a world can do it