The order of definition of pseudo-classes for the anchor tag is crucial.
In Firefox I noted that if you define :visited after :hover, you may not get the style you expect when hovering over an <a> element. That’s logical, if you think of it. But it can be confusing because the Inspector seems to ignore the style for :visited, leaving us clueless.
Looking for clues I checked Chrome too. The problem did not occur there, but that was because I hadn’t visited the page the link was pointing to yet.
The recommended order is
:link:visited:hover:active