Thank you! Now I found and fixed it.

Thank you so much! I disabled Smush and now it is working well.

Thanks

Or advice to make this same as the plan.

This is the page I am working with.

Now it works! Problem was in child theme CSS. It is fixed now.
Thanks. You can close this thread now.

1. Yes, I do have that Shrinking Header on (Header > Header Behavior). But it is not working.
2. Thanks, this is now solved.

Also some headings has wrong color and size.
Like Ohjelmistossa on frontpage

Caption should not be red – nowhere!
Here are some snip from Chrome and Edge. On Chrome it is just like it should be. On Edge and Firefox browsers it is wrong.
I have tried that on many different computers.

I tried to disable that and everything went wrong. I had to update backup copy.
But I can handle this: I just make those pages again.

But what could I do for that problem: on Chrome browser fullwidth easy slider caption is just like its hould be (white and right size) but on Edge or Firefox it is red and too small?

It looks like there is no background color on small screens.
Here are temporary admin logins for one site:

“It seems to be working correctly on our end now as shown in the screenshot below. Have you managed to find the cause of the issue? It might be a z-index issue based on the screenshots above. Increasing the stack order or the z-index property of the second section should fix the issue.”

I’m not good at coding. Could you please tell me exactly what I need to do. Thanks for your help again!

This is solved!

I have not managed to fix it. The problem is only on small screens.

Yes, thanks