I just was on a ride and all of a sudden I could only shift one gear up and down (in this case it was the 10th and 11th respectively the 21th and 22th). If I try to move the shifter further up (so up to the 9th and further) it blocks I cannot do it same problem with down shifting.
At home I tightend the shifter cable at the rear derailleur and now I can shift the 6th and 7th gear but nothing else. If I try the shifter does not move as above.
Any idea what the problem might be. I have the Grx 810 Group and the bike is about 5 month old, so it is not a brand shifting system.
Any help is welcome so I can get back on my bike.