end crystal can't be placed if a marker is present

How to reproduce

/setblock 0 -60 0 obsidian
/summon marker 0 -58.5 0

It’s not possible to place end crystal on top of the 0 -60 0 block. Run /kill @e[type=marker] and it’s again possible to place crystal.

Related block (light, structure_void) ticketMC-222794

Unsolicited thoughts;

I’m assuming it’s true for all entities, like players, mobs, items etc. I’m guessing it comes from either something PVP related or to prevent the player from trapping themselves inside the hitbox.

Out of the “special” non/semi corporeal entities (area effect cloud, armor stand with marker=1, interaction, text/block/item displays and markers) markers and armor stand{marker=true} should hopefully be exempt if fixed. The others are not as clear cut imho.