No problems, I appreciate the support. I have a child theme – because of customization. Although I did it the other way around, I first customized the sitye and then realised I had to make a child and had that done for me.
But I guess, it’s just the same: I only need to know in what file the code that is setting the title-tag to “Featured Image-1” is. I’d say I can program that in, because I will probably almost never change these pictures.