The pivot point (where the bolt goes through to the hanger) on my derailleur is almost jammed solid (Shimano Tiagra 4600 I think).
Took whole derailleur off bike, and needed leverage of long allen key just to get it to pivot. Tried to work some oil in there and it just about moves, but not decently.
Seems that the internal gubbins are held in place by a circlip (blasted pingfuggits).
Any suggestions?
also, would a GRX long cage rear be compatible with Tiagra shifters?