First things first, I am not very good at mechanics, so if my question looks very inexperienced, sorry for that.
I bought a road bike with shimano ultegra r8000 and after 2 years during a descend I wanted to shift up the front derailleur but I just heard a click and it didn't work. since then I feel a big resistance when I press the lever. The shifting to the smaller ring seems fine (I can press the lever), but the other way around not. I wanted to investigate it a bit before I go to a mechanics, so I looked inside and this is what I saw:
I marked on the picture that little black rectangle which seems to stop the lever agains shifting up (doesn't move at all)
This is why I thought it might not be an issue with the cable. My question would be, is it some problem that is easy to investigate from here and I can fix myself, or it is better to bring my bike to a service?
Many Thanks, Mate