The angle of the pto shaft can be very finicky if it's slightly off. A previous post mentioned a slight downward angle.
I have a feeling mine is off by this same amount based on how close the right guide wheel is to the right rear tire. I plan to go through this in detail in the near future. Thanks @dieselshadow for the details in explaining this.
You are missing the adjuster bolt. Yours looks pretty clean and fresh so I would guess the dealer didn't install it adequately. It happens on occasion. Look around your yard, you might find it, but you'd be looking for the bolt, which probably still has one of the nuts attached, a washer and the second nut.
Thank you so much! And now I know the torque spec is 40nm=29.5 lb.-ft so it won’t happen again!The bolt part number is 19M7167. 71 cents at my dealer. Size is M10x25. It doesn't list the pitch but I imagine 1.5mm. Yes, we have a member or 2 that had to adjust the linkage so far that they had to remove the rear bolt and are only running 2 bolts. No ill effects that I've heard of.