Since you are using Astra as your theme, this is also responsible for the output in the frontend. I would recommend that you contact their support forum with your request: https://projectdmc.org/support/theme/astra/
I was just looking at the WordPress astra forum and not finding much. I’m thinking the source is the CSS, but I’m not that well versed in CSS. I’m a designer, not so much a web builder. I’ll follow your link and search or post there. Thanks for the reply! I also want to restore some backups to see if I just missed the problem earlier. There has to be a cause/effect. 🤷♂️
Yes, I was searching that forum as you were replying. I’ll copy and paste my post and see if some can identify the source of the problem. Also considered switching to a different template to see the result. But I trust you are on target with the source. Also I have a pretty good understanding of the settings and applying them to the various formats. It’s a very simple header, so nothing very fancy. Just a field with…. A pesky background image.