I’m quite puzzled by this problem, which can be reproduced in our instance after upgrading to v2.4.0.beta1 +225 as well.
- https://discuss-space.wmflabs.org/ can create local copies of external images, except from https://space.wmflabs.org/. File format and size don’t seem to be relevant.
- Other Discourse instances can create local copies of images from https://space.wmflabs.org/
???
We don’t even know hot to debug this. There is nothing we have found in the diffs or error logs in Discourse. Strange.