Partitioned Landscape / AutoMaterial not rendering.

Hello. I am having an odd issue with my landscape automatierial suddenly breaking randomly, leaving a random patch of landscape as the default grid pattern (img 1)

I have seen that one fix is to ensure that my texture samples are set to wrap. However, I am not using Texture Samples but, rather, material functions: (img 2)

As you can see by the code, parameter texture objects are used. (Img 3) As such, I do not see an option to ensure ‘wrap’ is selected.

This code isn’t of my design, but that of UnrealSensai (Unreal Engine Landscape Master Material Tutorial - UE4 Tutorial - YouTube) I have asked hi9m about this issue but have yet to receive a response and am hesitant to continue working on my project unless this is a project-breaking error.

Does anyone have any experience with this and can offer a solution?

Cheers