Adjusting uPVC Door Hinge Adjustment

[Cadder]

Hi all,

We have bi-fold doors to the back of our 8 year old house. The last year or so the single door has been sticking, especially on warmer days. I looked online to see how to adjust the hinges and there's nothing that covers the type of hinge I have. At first glance they look similar but the adjustment method is clearly different. Here are some photos I took below:

Spoiler: Top Hinge

Spoiler: Middle Hinge

Spoiler: Plastic Cap Removed

As you'll see, there isn't a screw underneath the plastic cap that can be adjusted with an allen key. None of the YouTube videos I have found cover this type of hinge.

Has anyone come across this before? I don't want to blindly faff with the hinge as I did something like that before and had the door stuck open until I retraced my steps. Thankfully it was a hot day.

 

[Cadder]

Thanks for the replies.
The hinge pin is plain top and bottom in all hinges - no allen key slot.
The grub screw holds the pin in place. I did have a little joy loosening the grub screw on all three hinges, then chocking the door up with wood and then tightening the screws again, but there's no way I can believe that is intentional design - three little grub screws controlling vertical door position.

I think there's something in @gc123 's comment - I might try loosening the screws on the door side of the hinge and see if there's movement. If so, I'll chock/jack up again and loosen all three.