Skeleton custom entity model showing missing textures?

[IreneThePotato]

- Minecraft version 1.16.3
- Most recent version of PureBDCraft texture pack (x128)
- OptiFine HD U G3 (for 1.16.3)
- No additional texture packs, add-ons, plug-ins, or mods

I've noticed that the spider models work fine. I don't know which other entities this effects however.

[HanFox]

Try upgrading OptiFine to the G4 preview release.