Custom Background Image not responsive

Hi Olivseo

put this code to your Child Theme style.css file
OR
Install Simple Custom CSS plugin and put the code there.
I’m doing this on my testing server.
It can get to some different behavior then here on my site.
It can happen that it is not working.
Then we have to look further.

body.custom-background {
    background-size: contain;
}

or

body.custom-background {
    background-size: contain!important;
}

Also read this article, so you will get clearer view.

Hope Im helpful
Let me know
Cheers
TR

Thank you for your help tahoerock. If I use the cody you gave me, the image is only contained to the content and not the whole page. If I change the code to

page.custom-background {
    background-size: contain;
}

the background changed back to the whole page, but then it is not responsive.

Ok, I got it. This fixed it:

body.custom-background {
	background-size: cover;
}

Thank you once again!

Hi Oliv,
Im happy you found the way.
That is why I put the link there, so you could figure it out yourself.
Let me know if you need more help.
Cheers
TR