I have a 2006 Lemond Reno I received as a project. It had the original components without wheels. I put on Velomax wheels. It does not shift well in the rear. It has Tiagra ST-4400 9 speed shifter, 105 RD-5501 long cage rear derailleur, 9 speed Ultegra CS-6500 12 – 25 cassette, and what I believe is a 9 speed chain. New cables and housing. When shifting from the small sprocket, when it gets to #6 it will skip to #7. No amount of adjustment on the derailleur barrel adjuster solves shifting issues one way or the other. Adjustment can solve that issue, but then it just makes shifting issues on other gears. Derailleur and chain hanger do not appear bent. I’m stumped. Any Ideas? Thank you.

The cable looks like it's mis-routed. For a 'standard' setup, the cable should run straight through, just passing in the groove. The 'tab' on the tabbed washer is not really used, it just aligns the washer, and is bypassed by the cable.

Here is an example.

Yes. That appears to be it. I rerouted the cable as you said. Some fine tuning and all is well. Thank you.

Yes, that's better, cable runs straight, through the groove, with no 'funny' bend.

Routing it more 'in-line' towards the center of the fixing bolt increases the actuation ratio of the RD. This effects the proper indexing of the system.

Great tip !!
Glad it all worked out !