Dear Laurent,
Thank you for reporting this issue.
We appreciate your detailed explanation and screenshots. From my test, I can confirm these is no issue. Since the carousel is designed for multiple images, when only one image is added, it might align to the left or appear outside the container due to CSS translate properties. When autoplay is enabled, it may attempt to slide, even though there’s only one image.
As a workaround, you might try adding more image to stabilize the display.
Best regards,