To reproduce: summon any entity
[media]Linked issues
is duplicated by 22
relates to 3
Attachments
Comments 9

This affects experience orbs as well, they're darker than usual.
But the darkness changes based on the angle its viewed at
The lighting is based on the players look angle. for example if you look top down on a mob, the top of it will be pretty dark.

Fixed in 19w41a.

This is not fixed on items rendering on entities (i.e. armor stands) and item entities themselves
(Confirmed 19w41a for items)
@unknown, then please create a new ticket for that. I consider this bug to be fixed since all other entities no longer are shaded incorrectly.

@violine1101 made MC-163260
Thanks! I also came across MC-163242 just now, which seems like a very similar issue.
Directional light positioned only upper.