Hi. This issue has just happened just now and I do not have any idea what might have caused it other than the update. I use this feature constantly and now that it's gone it's driving me nuts. The middle mouse button still works but the 4th and 5th mouse buttons are now mapped to previous page and next page in Firefox. Operating system: MacOS 10.13 Firefox version: 92.0 Mouse: Logitech MX Anywhere 3 Thanks