Blocky landscape rendering

Hi, as a beginner I am still exploring the things in Unreal engine and its vast capability. With that in mind, I started a small project for an android game on the same.
After creating the landscape I ran it for checking how it looks on mobile and it was as shown in Image.
I have been referring to ActionRPG for development using the same materials just different textures from mega scans. The image below has the same material for all 3 landscapes. I am assuming I am doing something very stupid.
After going through the guides I could find online and other places I see landscape overall size is affecting the pixelation.
I hope there is a better way to make a larger landscape with the same result as in image 1.

I have been trying for almost three weeks to resolve the issue.
Have already been through custom UV. Since its ActionRPG material, it’s working the same way.
My material renders the same as there’s. What I am hoping for is not requiring to make multiple landscapes of image 1 size, instead of one landscape of the same size as image 3 without pixelation.
If anything else will be required please do suggest and will do my best to provide.