The plot gets thicker...
The problem remains. However, I have found if I wait about an hour or more it works, but only once. That is, if I leave the site open on Forum (or any other page) and come back in 1 or 2 or 3 hours I can click on Fishing Times and it works, But if I then go back to Forum I cannot get Fishing Times to open. But if I then wait again for a few hours it works (but only once). If I wait that few hours and refresh the Forum page, I cannot open Fishing Times.
I am not a big internet surfer, so I just looked for a dozen or so other sites that have multiple pages. I have not found another web site that duplicates this problem. I have tried 5 or 6 different browsers and only Firefox 44.0 under Ubuntu is doing this, that I can see.
I have installed Chromium (the Linux version of Google Chrome) and it works a treat. But only Firefox is supported by Canonical (Ubuntu). I would rather be using a supported browser so that I don't have to manually check for security updates etc.
itsaboat mate...Life is just a boat and then ya marry one !