OK, just looks like the lock out spring is misinstalled, there should be spring tension forcing that arm into the recoil. Simply remove the bolt holding the black lock out arm and find where the right side (in your picture) of the spring should be positioned on the block so the spring tension forces the arm into the recoil…
Be sure to get that grey lock out cam/lever behind the black lock out lever before bolting the lock out lever back down. So, when in neutral, the vertical shift lockout arm will push the grey cam against the black lock out lever, overcoming spring tension, forcing the lock out lever out of the recoil. The vertical shift interlock arm will be out when in either forward or reverse, allowing the spring tension to push the black lock out lever into the recoil, jamming it.