Ultegra Shifters - What have I done wrong?

[Grant Fondo]

With fresh eyes and taking things a bit slower, just reseated everything and all working fine now. Thanks all for great advice 👍🏻

Great news!

 

[Gunk]

Set the RD up using the last but bottom gear and then adjust it so it slips on to the bottom cog, using this method it will always shift perfectly.