Spark Knock (2016 66.000mi)

Hi, just like the title says I've got spark knock. I came to this forum with this problem at 35,000k miles and now the issue is back and I'm wondering if anyone else is having this problem. I specifically hear the knock at about 3200rpm in sport mode. I've switched to mid grade gas and the problem persists.

My preferred dealer says there are two valve cleaning options available. One is a solution that is administered through the manifold and the other involves removing the cover and scrubbing the valves and cylinders with a brush.
'15 6, '06 5
Nope, not having that problem. If the knock is knock, and if that*s being caused by carbon buildup, then a product like Red Line SI-1, Chevron Techron, or a CRC product whose name escapes me would be good, inexpensive options.
Portland, OR USA
2004 6s Wagon
I would run a tank of premium grade. Perhaps cycling the ECU (disconnect battery for 1 min) and allowing the car to relearn with the higher grade fuel.
DO you drive mostly city (stop and go)?