Button image not rendered, only showing background color

Hi,
I am making a game prototype using blueprints and am facing this issue.
I am using images in buttons in the UMG for main menu/ options etc.
Some of the buttons are rendered fine but some only show the background color and the button image is not rendered at all. This happens to different buttons in different devices. I am using two devices, 1. Micromax Canvas Magnus A117 and 2. Moto G2.

Left is A117 Right is Moto G2

54941-start+button+_2.jpg

54942-restart+button.jpg_2.jpg

As you can see the start button is fine in Moto G but not in A117, and restart is fine in A117 but not in Moto G.

BUMP
Anyone?