I wore out my Ultegra 6600 triple shifters and installed 105 5803 shifters, brakes and front derailleur. The Ultegra rear shifted three cogs at once. The 105 shifter only shifts two. I’m referring to shifting to the larger cogs. Is this correct or should it shift three? It appears to try to go to the third cog) but then drops down to the smaller cog. The shifter is shifting to the third cog but then retracts the cable. When shifting to one or two gears, the shifter works perfectly.