From 1.19 geckolib 3 using EntityCutout rendertype:

1.20 geckolib 4 using EntityCutout rendertype:

1.20 but from below, the lighting actually does look correct.

Tried various render types, nothing is unchagned.

It looks like the lighting is baked in from the wrong rotation? As if it were upside down?

possibly related to #448?

@baileyholl You'll be happy to know I finally fixed this lol

Looks like this also applies to models held in the hand, for items as well (this is including the latest fix for GUI lighting)

and in first person, the lighting is upside down in hand like the block

Very interesting

Can you join the discord so it's easier to communicate lol