Yes, you're right, I had to disable css optimization on the platform which provides the ads. No the slideshow works.
I can see the magnifier icon now back but search doesn't work any longer. Index of smart search shows a warning that the index needs maintenance. But when I click on optimize, I get the following error:
1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')' at line 5
Do you know how to fix this?
Just now I heard from another developer that the searching problem occurs after the Joomla 4.2 update.
Thanks a lot for your help!