Sure, but that same footer image is also referenced as main image in the meta-tags (so it might also show up when sharing on social networks).
based on that it *looks* like something (your theme? your SEO plugin? a code snippet?) is using Autoptimize’s API to alter the metabox settings to have AO preload the featured (?) image and in doing so incorrectly overriding the image you set. to troubleshoot further you’ll probably have to disable (and re-enable) plugins one by one (and/ or change themes briefly) to find out which one is responsible for this (you can check the HTML source, it now has;
<!doctype html ><html lang="de-DE"><head><meta charset="UTF-8" /><link rel="preload" href="https://www.fehnblogger.de/wp-content/uploads/2021/02/fehnblogger_bildpost.jpg" as="image">
but it should have
<!doctype html ><html lang="de-DE"><head><meta charset="UTF-8" /><link rel="preload" href="https://www.fehnblogger.de/wp-content/uploads/2022/11/19.-November-2022-fehnblogger-0410-2-696%C3%97392.webp" as="image">
feel free to keep me posted here, I’m always interested in finding out what other software is hooking into AO and helping them improve ??