Right okay!
That post you sent was useful after all, but I was able to do it inside of the texture instead of through code.
I watched an older video and at the 42 second mark he shows how to set the filter to “nearest” - just like that code is meant to. Video linked below.
Its not in an obvious place in Unreal Engine 5 compared to 4, to find it is it under texture → advance and it is there (shown below)
Thank you for all your help!