Can't set additional mouse buttons in shortcuts menu

It's something I'm just checking some additional information about on my side. But @papzman do you also have the option to rebound your mouse keys as a keyboard input? That could also help. For example, with my steelseries mouse I have rebound some buttons: 

I have just tried it with my own mouse and tried playing around with settings and it appears even when binding a key on my mouse to space the input was not recognised. We'll get this looked into further.

Thanks @Michael Sant, that would be much appreciated.

I've used AutoHotKey to rebind that extra mouse button to spacebar when Football Manager is open and it seems to work - although not as smoothly as simply pressing space.

Hopefully an in-game solution will be found!

Once again, your help has been much appreciated.

Good to hear AutoHotKey has provided a workaround. Quite possibly one I might use myself but our QA team will look into this further.

I had a similar issue that was logged with either FM22 or FM21 - We found the issue was with how some of the modes of mouse software work with assigning commands to mouse keys - for example the Logitech Gaming Software for my G602 mouse has two modes - on-board memory and automatic game detection. If set to automatic mouse commands would work, but if mouse is set to on-board memory mode FM doesn't correctly pick up what command is assigned to the mouse button, but it does in the other mode.

For example, I assign Ctrl+L/R to Mouse buttons 5/6 for the quick flicks, which works in Automatic mode, but in Memory mode FM treats the mouse buttons as only assigned to Left/Right keys without the Ctrl modifier.