18-55 stuck at f/3.6 maximum aperture

[Zach]

My 18-55 f/2.8-4 is having a problem: at 18mm, the maximum aperture that is displayed on the screen (if I turn the ring all the way left) is f/3.6. I can't get to f/2.8.

What's odd is that if I extend it all the way out to 55mm, it still displays the aperture as f/3.6, which should be impossible. If I then click the aperture ring right (while keeping the focal length at 55), when it clicks over to f/4 there is a noticeable darkening of the exposure, which means that when it says f/3.6 at 55mm that is not the actual physical aperture setting at that moment.

I had this problem once before with this lens over 2 years ago and had to send it in for a repair, so I suppose I'm being a bit optimistic in thinking that this time there might be an easier solution, but since it was working fine yesterday and hasn't even left the house since then (i.e. there is no conceivable reason the lens would have started manifesting this problem in the last day that I can see) I thought it worth asking. The only thing I've done since then was to update my camera firmware (X-T1). If it's malfuntioning again I certainly won't be paying for a 2nd repair.