I‘m aware of the current federation issues that might also be the reason for this issue but I noticed that while federation of posts from feddit.de works sometimes as well as posts and comments from other instances no comments from feddit.de are syncronised at all.
It might be better to ask there but as I do not have an account there I thougt I first ask here if this is already known. Does somebody else also have this problem?
I noticed this today on a post about the federation issues in !main@feddit.de
The post has a lot of comments and upvotes when it's opened directly on feddit.de
When opened from tchncs, it has no comments and only a couple upvotes.