I actually contacted them first, I tested it in Twenty sixteen, and I had no issues…
I will figure out what it is and will let you know…

Thank you!

Thank You!
You are the best!

Ok the theme was update…

Just to explain what happend on my side: The site was on newest theme, but had all these issues,
I reverted to a previous backup(older theme files) that sorted some of the issues, now the theme is on the newest version, but I still have Issues…
it was mostly to do with images and the headers

Thanks, Will check