Comment permalinks not fully embedding

[JodanJodan]

The following permalinks both resolve to the same comment/URL:
https://old.rxddit.com/comments/1iui7lx/comment/ml8bjpz
https://old.rxddit.com/r/ASRock/comments/1iui7lx/comment/ml8bjpz

Is it intended behavior that the first link results in a different/truncated embed?
I often copy links using RedReader, which doesn't include the subreddit prefix in the path.