I can't make cross-post work properly

cross-posted from: https://lemy.lol/post/3174066

I shared a post about my instance.

Then I hit the cross-post button, chose the community, language and then submitted the form. Although new post created, there is no "cross-posted to" area on both original or target post.

For example here, you can see which communities the post cross-posted to. What am I doing wrong?

Update: looks like both posts should have same URL for crosspost to work. https://github.com/LemmyNet/lemmy/issues/3827