"Source" links behave in an odd way

[winks]

Something odd seems to be going on with the [Source] links under posts, could be a tiny CSS issue, but I've not found it so far.

So middle mouse click to open new tab works for both the author link and the source link.

But dragging the link to Firefox's tab area to open it in a new tab only works with the author link (and with 90% of links on all websites, unscientifically observed).

Here's some source for comparison:

<a class="user" data-turbo-frame="_top" title="..." href="/remote/actors/...">SOME AUTHOR</a> shared a note by...

<a class="source" target="_blank" href="https://mastodon.social/..."><button class="ui mini iconic button"><i class="external arrow icon"></i>Source</button></a>