Some blocks that don't use a full block geometry may stop rendering correctly if they have point light enabled.

I discovered this issue with Glow Lichen and Amethyst Clusters.
To demonstrate, I have a glow lichen and amethyst cluster with full PBR textures and without point lights, they render correctly:

But once you enable point lights for them via global.json, the textures stop rendering correctly, amethyst displays incorrectly from certain angles, while glow lichen is completely missing its texture with the point light hovering over it.

Steps to re-produce:
1. Create a resource pack and enable point lights for the following blocks IDs: 
"minecraft:glow_lichen"
"minecraft:amethyst_cluster"
"minecraft:large_amethyst_bud"
"minecraft:medium_amethyst_bud"
"minecraft:small_amethyst_bud"
Or you can use the global.json file I've provided in attachments, can be used with the current 1.21.40.23 preview by placing it in the root directory of a PBR-capable resource pack in a point_lights folder.

2. Place the blocks down in world and observe.

Expected results:
Blocks should render their textures correctly from all sides

Observed results:
Block textures will not render correctly as demonstrated earlier.

Notes:
This bug may apply to more blocks, I've only discovered it with glow lichen and amethyst clusters for the time being.

Glow lichen's point light is also floating too far away from the texture's plane, it would be a good idea to have hard-coded adjustments in place for some vanilla blocks such as glow lichen.
Ideally, the point light should be closer to texture's actual surface instead of hovering roughly half a block above it.