entities disappearing

Whilst playing in Survival I was attacked by pillagers and I got killed. upon respawning one of them as well as some of my items  turned invisble not showing any hitbox or getting affected by the "glowing" effect. Villagers disappeared too and some of them appeared again as zombie villagers after beeing killed by zombies which could still target them. ( which i noticed to the zombies bunching up in front of a door. eventually the door openned and a bit later i discovered zombievillagers Inside. but there were no sign of any villagers Inside before that.)

my items could be picked up but wouldnt show up on the ground and the pillager could still shoot at me but only the arrows would be visible.

it also occured on a superflat world with slimes. I randomly started taking damages after respawning but there were seemingly no entities close enough to attack me.