I have about 7250 miles on my 2018 Nissan Kicks SR. I took it in to the dealer (SoCal) this morning for a 10,000 mile service. I also reported the intermittent obstruction sensor on the front of the car (been like that for the last 3000 miles) and he asked me if I looked at it? He was suggesting that once the alert surfaced on my dash, I could have looked through the front grill and visually inspected the sensor for debris, water, or an obstruction. I said, "no" because I wasn't sure where to look. I watched him as he went out to my car and positioned himself in front of the driver-side headlight and peaked into the grill. So, I can only assume that is where the sensor is.
When I asked him about the repair, he said it can go two directions: First, they run a diagnostics test to determine if it's a software or hardware problem. A software problem was solved with an electronic update. A hardware problem was solved with a sensor replacement. But he wouldn't know a timeline until they ran the diagnostics. Mine was the latter. He did estimate that repair for about 2 hours because the replacement required removal of the bumper and grill.
So, yes - it is a problem, and yes - my Nissan dealer accepted it as a warranty repair. The alert did not surface during the ten mile commute back to my home.