Header Image Issues

I have a spent a week trying to fix the header image on my home page. It was sized perfectly on all devices, but all of a sudden, it is not viewing properly on a mobile phone. I need to resize it for mobile. I also don’t like how it does not scroll with the rest of the home page on any device. Ideally, I want the header on the home page to be exactly like it is on the other pages. I also need to be able to move the tag line and logo on the home page without moving it on the other pages. It is the Twenty Seventeen theme. Please help!

The page I need help with: [log in to see the link]