Open the computer's mouse program and check the settings.

Hello RONSAN, try Firefox Safe Mode to see if the problem goes away. Firefox Safe Mode is a troubleshooting mode that temporarily turns off hardware acceleration, resets some settings, and disables add-ons (extensions and themes).

If Firefox is open, you can restart in Firefox Safe Mode from the Help menu:

• Click the menu button , click Help and select Restart with Add-ons Disabled.

When the Firefox Safe Mode window appears, select "Start in Safe Mode".

If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension, theme, or hardware acceleration. Please follow the steps in the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article to find the cause.

To exit Firefox Safe Mode, just close Firefox and wait a few seconds before opening Firefox for normal use again.

thank you

Thanks for both replies - I received the mouse setting suggestion first, modified the mouse settings (don't know why it would have changed - I didn't do it) and everything is working with a single click - if there is any change I will check that first and then try the safe mode suggestion - again thank you both.

Glad to help. Safe Surfing.