Resolution: This is mostly a result of inadequately set up derailleur limit screws and these would require modifying. It can also be due to a bent derailleur hanger The furthest inboard the rear derailleur should have the capacity to transfer is The purpose where the higher jockey wheel is sitting https://collinzfhih.eedblog.com/32908052/indexing-bike-gears-no-further-a-mystery