The usual… McLaren P1 gearbox hell

Because I never learned to start anything from square one this is my first ever Lego Technic set… I rebuilt the gearbox once already during the build as it was sometimes getting stuck (may still be an issue, unsure, but not the problem I need help with). After finished the build, when in gear and with the driveshaft engaged the engine doesnt move when the car is rolled, i’ve attempted to locate the issue and think i’ve narrowed it down to the green clutch gear simply not moving. Is this wrong...