This issue may have come about with the latest esr update. If that's an early release channel, how can I switch back to the normal release channel and thus resolve this issue? Screenshot attached.

128.6.1esr is the current version and not a 'beta'. Uninstalling and reinstalling would be an option but you need to safeguard all your profile files before continuing. That wouldn't be guaranteed to resolve the issue, though.

Does right-clicking on the link and choosing the relevant command work?

See https://support.mozilla.org/en-US/questions/1489899

frisée and sfhowes- thanks for the feedback!

frisée- right-click only allows saving the image sfhowes- the reference your gave confirms the issue is a bug due for fix.

-D. Abel

Since this "feature/bug" was introduced, I was not aware of how many links from newsletters or service providers had graphical button links, which now do not work as expected.

So, instead of "left-click" to open the link in Firefox, I now have to retrain the reflex response to the link to "right-click → Open Link in Browser"

Maybe someone thought this was a good idea, but I personally don't think so. Better yet, switch it to "right-click → Zoom image view", as that would probably be the less frequently used scenario.