Mobile Page Banner Images are Awful

[Seratsuki]

I'm working on a Sharepoint site, and everything looks fine on a desktop, but images are blurry and cut off when I look at it on my phone. Here are screenshot examples: 

How it looks on my phone in Chrome: 

On my desktop monitor, using Chrome it looks fine. 

I made sure in the site settings that "mobile browser view" is active, but it doesn't seem to affect pages. Any help? It looks unprofessional for our mobile users. 

[#2]

So I have noticed that if I use the stock images provided, they seem fine when switching to mobile. So that means what's going on is incompatible image sizes and focal areas. 

Can someone please give me optimal image sizing and an idea of where I should place text so that it can be visible on both devices? That would be helpful. 

[#3]

I’m having the very same issue, if I find a solution I’ll notify you.