Images without file extension are not downloaded (broken after import)

Hi Support Team,

I am currently experiencing an issue with image imports.

Images that do not contain a file extension in the URL (for example: https://example.com/img/image-123) are not downloaded correctly.
Although the files exist and are valid images (e.g., image/jpeg), the plugin does not save or rewrite them properly, which results in broken images after import.

Additional details:
• The image URLs have no .jpg, .png, .webp etc. extension
• The server returns correct MIME types (e.g., image/jpeg)
• The images sometimes include size parameters like ?width=1500&height=843
• The files are downloaded partially (file size exists), but aren’t recognized or rewritten in the content, resulting in broken images in posts
• Example URL: https://s.zentrum-der-gesundheit.de/img/leinoel
• Even when forcing download via custom script, the system does not append a valid file extension based on MIME type

Expected behavior:
• The importer should determine the file type via MIME detection (e.g., image/jpeg → .jpg)
• The image should be saved locally with a valid extension
• The path inside the post should be replaced with the local attachment URL

Right now, images without file extensions are not usable after import.

Could you please advise if there is:
1. A built-in setting to enable MIME-based file extension fallback?
2. A filter/hook to force saving images with a proper extension?
3. Or an official workaround for this behavior?

Thank you in advance for your support.

Best regards,
Rene