I’m hoping for some help on a gear shifting problem.
Running 9 speed XT.
The gears shift up the cassette, to the larger sprockets, with no problems, but shifting the other way is bad, it won’t even try to get on the 11 tooth.
From this I determined that it must be sticky or worn cables, so changed them, only to find the same problem.
The cables are slack when shifted to 11 tooth, but the chain does not move, I can manually push the mech and it then changes, so I’m happy with the high and low limits.
Help please?

How old is the mech? Might be a worn-out spring.

Is the dérailleur hanger straight?

APF

Damaged outer cable housing affecting new cable too?

Fitted new inner and outer, the mech is about 6 years old, do the springs wear out? the mech does not seem to be sloppy or loose. the hager looks straight and in line with the gears.

I had similar issue with my old 9 speed rear derailleur. Changed cable inner + outer, spent a number of rides tweaking the adjustment, sometimes it would work well, other times it didn’t. Changed the derailleur and issue was solved. If you have tried the full set-up procedure, changed the cable, and the mech hanger is not bent, then try a new derailleur as you can get them for a reasonable price online.

oil up the mech. it might be dry and not dropping correctly.