Minecraft wiki entry for Development_versions, associated text: MC-42192 – WitherSkulls flash for a brief moment when being summoned.
MC-44634 – Invulnerable Fireballs are invisible/being client-side rendered on hit.
MC-51573 – Hostile mobs continue to follow/attack player in Spectator mode.
MC-64444 – Wither skulls are being rendered for a moment.
MC-65697 – Explosion force on entities is directionally biased.
MC-66089 – Explosion physics changed, range of some TNT cannons greatly reduced.
MC-74686 – Marker armor stand block placing issue.
MC-74866 – Chunk flickering (only Intel HD Graphics / Driver version 10.18.10.3958).
MC-75722 – Buy a realm has no "Back" button with no internet connection.
MC-75885 – World generator crashes when generating pumpkins (e.g. seed "Cows").