I get around this by; When I find a link I want to check out, I open it in a new tab/window. Then when I am done, I close it and am back where I started.

Yeah I could do that, but other browsers don't suffer from the same problem and I am posting the fault because I am trying to contribute to the improvement of that general issue of this platform...

Sure, but the Mozilla weakness persists.

I have no issue click and load one page of it and I can close it. But I do see "x" boxes where there are ads on it. So that could also be part of your problem.

You may have got lucky. Sometimes it doesn't do it. What I am saying is that after clicking on an article to go back to theguardian home page - within that same tab - is usually quite difficult. If you press the back arrow it does nothing, nor does the backspace button. The only way to return to your previous page - which puts you at exactly the same place you left from- is to click and hold the back arrow, which reveals your tab's history, and then move the arrow down to the last incidence of theguardian.com home page - often 5 lines of history down. Other browsers do not suffer this same issue.

Do all these pages have the same URL?

Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration is is causing the problem.

• switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Appearance
• do NOT click the "Refresh Firefox" button on the Safe Mode start window

• https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems