Summery:
A spawned wither skull is facing the wrong direction. In F3+B, its hitbox looks in the right direction but not the visual of the skull, this seams to be rotated 180° vertically.
(see images)

Steps/commands to recreate:

/summon minecraft:wither_skull ~1 ~1 ~ {NoAI:1b}

Also used:

/execute rotated as @s anchored eyes run tp @e[type=minecraft:wither_skull,sort=nearest,limit=1] ^ ^ ^ ~ ~

Please let me know if it's a duplicate, couldn't find any.