Hello,

I saw the screenshot you attached.

The Custom CSS I provided is to display the Image full size as it is displayed on the Desktop versions.

And if we try to change the size of the image then it will repeat.

If you still want the CSS then try adding the following Custom CSS.

.page-title-default {
    height: 150px;
    background-size: contain;
    background-position: center center;
}

Best Regards