It appears that this mod causes an issue with how hoppers and cauldrons render while in the nether. I've only experienced this bug with PBR shaders enabled, and the rendering is perfectly fine in every other dimension.
Here is how the blocks are rendered without the mod:

and with the mod:

This is resolved by disabling PBR in the shader settings, so it seems to me that the way this mod implements the texture map for better grass in the nether is the cause for texture rendering to fail here.

If any additional info is needed. like log files etc, let me know.

Can confirm, a bit annoying but not a big issue.