I'm experiencing an issue with my 3-year-old Shimano 105 ST R7000 front derailleur. Most of the time, it's difficult to shift, and the shifter often fails to engage properly.
I’ve already replaced both the cable and housing, but the shifting remains hard, and most of the time it does not shift at all: the pawl jumps out of the ratchet gear and fails to engage (as seen in this footage: https://imgur.com/a/hoQrRpS). Interestingly, when I detach the cable from the front derailleur and manually apply slight tension, the shifter works fine.
Manually moving the derailleur cage to high positions works fine, although there’s considerable tension in the spring, which I assume is normal.
Initially, I thought it might be the same issue as described in Shimano R7020 shifter broken - no audible click when shifting where the spring was not holding the pawl. However, correctly repositioning the spring did not solve the issue.
I also tried putting some plastic spacer as seen in this video but it didn't change much.
Could there be something else I’m overlooking, or does this sound like a more significant mechanical problem?