So Porrus mushroom textures r broken while using server texture pack[BUG]

[SciathGH]

Describe the bug

While using the texture pack the server provides some mushroom blocks are null blocks in textures
To Reproduce

use server resource pack on porrus
Expected behavior

Visible null blocks
Screenshots

System (please complete the following information):

• OS: [e.g. Windows] Windows
• RAM: [e.g. 8gb RAM] 8gb
• Minecraft Version: [e.g. Minecraft Java Edition 1.16.3] java 1.16.3

Additional context