Images cropping strangely in mobile

Hi there, some of my images are not resizing to fit width in mobile view. Should I be exporting images to a certain size across all pages to stay consistent? Also open to some CSS tricks. It looks like the height is set to a fixed height. Is there a way to make it to fixed width so the entire image shows up in mobile view instead of getting cropped on the sides?

Examples below...

@dday Are you on 7.0 or 7.1? And are these image blocks or background/banner images?

@holdspacecreative I'm on 7.1 ... and I believe background/banner images. Is there a different trick to how to solve viewing in mobile for image blocks compared to background/banner images? Thanks!

I am also facing the Same Issue. Image become blurry in mobile when I upload on store. https://fajasfits.com/collections/fajas-shapewear