solved: answer in comments. short answer is Piper needed to be installed.

I installed solaar.

It calls my mouse a m500s. In Solaar i set key/button diversion (there are 2 drop down menus) one i set to forward button the other i set to regular. This causes one of the buttons on the side of the mouse to act as the forward button on a web browser.

key/button actions drop down menus (2 drop down menus) I set to back button and mouse back button.

when i run

xev -event mouse | grep -b2 button

4319-ButtonPress event, serial 25, synthetic NO, window 0x3000001, 4381- root 0x1e5, subw 0x3000002, time 13605046, (43,38), root:(75,102), 4452: state 0x10, button 9, same_screen YES 4494- 4495-EnterNotify event, serial 25, synthetic NO, window 0x3000001,

4708-ButtonRelease event, serial 25, synthetic NO, window 0x3000001, 4772- root 0x1e5, subw 0x3000002, time 13605214, (43,38), root:(75,102), 4843: state 0x10, button 9, same_screen YES 4885- 4886-LeaveNotify event, serial 25, synthetic NO, window 0x3000001,

that is the result if I hit the forward button on the side of the mouse in the test window. but no result of hitting the other side button (the back button).

I know that the o/s isn’t recognizing the button press but not sure how to get linux mint to recognize the pressing of the button.

any thoughts on how to fix this issue?