2015 XC60 T5 rough idle on cold start and automatic start/stop disabled

[towanas]

I purchased a 2015 Volvo XC60 T5 with 70,000 miles about 2 months ago. Within a week, as I was cold starting the car for my morning commute, the car had a really rough idle, almost to the point of the engine dying, and then the check engine light came on and stayed on. Dealer diagnosed as #1 fuel injector, fuel pipe, and o-ring...all replaced. As I am unfamiliar to the features of newer cars, I realized after I got the car back from the dealer that it has the Automatic Start/Stop feature, but the feature is not operating. The "my car" computer says it is disabled due to "Electrical System." We checked the battery to make sure it is the correct one, as that feature requires a special battery. It is correct and has a sticker on it that says it is 14 months old. I have not returned to the dealer about the inoperable start/stop feature. But this morning, about 1 month after replacement of the fuel injector and related parts, I cold started the car again and had the same rough idle with near death and check engine light illuminated again. I am now curious if the two problems could be related? Has anyone had this issue before with the cold start? Thanks in advance....