Hi, I have a fresh Lemmy installation (0.19.17; lemmy and pictrs runs as docker containers; ssl). Everything works, federation works. No errors in lemmy logs.

When I create a post with and external image (link in “Create a post” URL field) - my posts are created normally, thumbnail - is also created. I checked postgres DB posts table and looks like both url and thumbnail_url columns have proper links to images. thumbnail_url has a link to resized image in pictrs. Looks OK.

But no thumbnail is created in those scenarios:

• Upload an image (Create a post -> Image -> Choose file), image is uploaded to pictrs but - no thumbnail is being created. url column in DB has a link to image file in pictrs. But the thumbnail_url has a value “NULL”.
• Same happens if i put an URL to a local picture (for instance https://my_domain/www/image.jpg). No thumbnail.

Looks like Lemmy somehow treats differently images stored in the same domain as Lemmy instance. And it doesn’t matter if I use URL to pictrs image or to some other image. If it’s in my domain - no thumbnail.

Everything else seems to work. I can attach pictures to posts, add picture as a community icon or banner, set a site icon and site banner - no problem with pictures.

Any idea how to solve that?