Collection header images -fixed background position

[KAillustration]

I recently used code to edit the sizing of my collection header images on just the mobile site. The code I used has worked perfectly on the image resize but has stopped my header images from having a 'fixed background position' so they no longer move on my screen. Can anyone tell me how to edit the the following code so it doesn't affect the animation setting? 

@media (max-width: 767px) { .animate--fixed>img:not(.zoom):not(.deferred-media__poster-button) { height: 60vh; margin-top: 0px; position: relative } }

[dmwwebartisan]

@KAillustration 

Please share your store URL & the screenshot of what you want!

Thanks!