featured image not visible on mobile view

Hi there,
featured images are not shown in mobile view just an empty space…
Any one else having this issue?

Issue checked on chrome for android and firefox for android

issue solved

this issue is caused by WP fastest cache’s lazy load feature… if any one else is having this issue disable it.
How can i troubleshoot this issue so i can reactivate it?

Thank you for sharing the fix, contact to the plugin author about this problem, you can also use other caching and optimization plugins with the similar features