My rear Di2 derailleur started to ghost shift on cogs 2-3-4. With the chain on the big ring (50t) and smallest cog (11t) I verified the upper stop limit was correct, derailleur hanger straight and jockey wheels (guide pulleys) line up with the cog. Same with the larget cog. In crash mode the derailleur shifts to each cog (up and down) okay but not on the road when I put load on the cranks. Shifts and runs fine on the 11 cog and on cogs 5 through 32 on either the 34 or 50 chain ring. It doesn't matter if I shift from 5 to 4 or 1 to 2 ghost shifting occurs. Any ideas or is my one year old RD in need of replacment?
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