SAFARI: Back keyboard shortcut same as bookmark 9

Hi, I'm having issues with safari 14.01. I have a logitech mouse with dedicated back and forward buttons. I have tried to set them up as the safari keyboard shortcut for those functions, but the back button isn't working.

The keyboard shortcut for the back button is " command + [ " .

Since I'm on a macbook and using a french keyboard, there is no " [ " key and it is done with a combination of: " Option + 9 ".

So the shortcut for the back button is "CMD + OPTION + 9".

However, this shortcut is already used by a bookmark (netflix in my case), which causes all sorts of problem and results in the bookmark shortcut most of the time, with the occasional back button shortcut working. I don't dislike netflix, but when I press the "back" button, I want to go back, not to netflix. Is there any way to fix this? I don't need the bookmark shortcuts and would like to disable them all together if that's an option.