For example, I created this post with this image hosted on lemmy.sdf.org as URL. The post never made it to !skiing@lemmy.world.
However, the same post with the same image hosted on pixelfed.sdf.org made it just fine.
This is just one example. I’ve made at least a dozen such posts and each time this happens without fail - unless the URL is something other than a lemmy.sdf.org-hosted image.
Not sure where to report this…
I have never had this problem, but it is obvious it exists from your comments here.
Editing to add: Now that I think about it, I’ve seemingly been the only one to be able to see or comment on some of @sundrei@lemmy.sdf.org 's posts on !tenforward@lemmy.world .