Featured Image Full is not work, custom image size is not work

Hello,

I am big trouble with full/original size featured image.
I search and try many ways to get answer.
Not work till now.
Can AnyOne help about that?

U used wordpress version 4.6.1, visual composer page builder, custom theme.

After tried many ways (include plugin deactivated), the image get full size at Firefox, Safari, IE.
Still not ok at Chrome. At chrome the image is still blurry and size is (1024x…) .. large size.

But, At Firefox, Safari and IE image is not sharp/full size when screen size is big (at 23 inches monitor). Chrome is not ok at all.

This is so strange and i don’t know how to solve this issue.

<?php
echo get_the_post_thumbnail($post->ID,’feature-banner’,array(‘class’ => ‘aligncenter img-responsive’));
?>

<?php
echo get_the_post_thumbnail($post->ID,’full’,array(‘class’ => ‘aligncenter img-responsive’));
?>

Link is here ..

https://revotechmm.com/mpt/en/home/mobile-services/base-tariff/

Thanks