@hrishikesh
I’ve also deployed the exact same files in a fresh Repo and Netlify-Site and also there, the images work.
EDIT:
I’ve compared the projects in the Netlify UI and found the culprit… There was an env var called NITRO_PRESET=netlify-edge that I don’t remember putting there (or why). I’ve removed it and now everyting works fine. I’ve also found a similar ticket that might help others fix similar solutions: Bug: Scheduled functions are not executed when Edge Functions are enabled using NITRO_PRESET=netlify-edge
Thank’s for your help and pointing me into the right direction!