Continuously scrolling background is not seemless, plz help

I got a professional designer to design a seemless background. He did it perfectly. The background image IS seemless. But when imported and run in Construct 2, it shows a thin white line between the next and the previous images which breaks the illusion that the background is seemless.

I am importing the image as a sprite and then applying bullet behavior in order to let it continuously pass by.

How can I fix this?

Thanks!

Maybe someone has a more technically articulate solution but, I do it with the image as a background object not a sprite but I have the same issue on occasion. I just adjust the size of the image by stretching it a little in C2. I have to play with it a little but can always get it to work.

Is your layout very wide?

what about using Tiled Background and stretch it to outside the layout.

Is your layout very wide?

what about using Tiled Background and stretch it to outside the layout.

This problem is very noticeable on Android (using CocoonJS), and not so noticeable on web. I'll try making it a tiled Background and also stretching it a bit as TheDom suggested.

the scrolling background size mus be: 32x32 or 64x64 or 128x128 or 256x256 or 512x512 or 1024x1024 etc...

Square.