The mods at GHMB kindly got back to me very quickly. Here is the message:

"GHMB is experiencing a formatting issue regarding page width on our Forum Message Board pages; the webmaster has been notified.

"There is a workaround available. Reduce the width of your browser page. If you are using Windows you can force a narrowing of the page width. Here is a quick video that will allow you to snap into a side-by-side page layout:

[www.digitaltrends.com]

"This should work in Windows 7 through 10. The narrower width overrides the link issue.

"A simpler temporary solution is to use the Windows key + left arrow or Windows key + right arrow to snap windows. This may be helpful on smaller monitors or laptops."

Off to try it...