Short-form links to Q&A don't show up in the "Linked" question list in the sidebar

Question

Links in comments (and maybe in answers) in the short form do not show up in the "Linked" questions list in the right sidebar:

https://mathematica.stackexchange.com/q/nnn

Links that use the full form do show up:

https://mathematica.stackexchange.com/questions/nnn

The same happens for short and long form answer links.

Examples:

1. The links in this comment from September show up in the sidebar.

2. The link in this comment from a few days ago does not show up in the sidebar.

I don't know if this is intentional, but it makes the short form seem deprecated. Can the old functionality be restored?

Answer 1

D'oh! It's because I was using an old script to generate the link. The script used the defunct HTTP protocol. Switching it to HTTPS fixes the problem.