I often don't see the feature when creating a new issue.

I think this might be because Github is using pushState() to make a single-page-app, so the script is not loaded because the @includes were checked when I was viewing an earlier page.

If that is the cause, then I suppose the workaround would be to @include the script on all Github pages, and decide whether to activate the script more dynamically (e.g. just after a pushState() occurs).

Might be a bit of a fiddle, but it's probably something that a few other userscripts are needing to do these days.

I'm sorry, but I'm reading issues created here. If your problem still persists, can you the issue to github repo.