My parking distance radar seems to kind of 'randomly' trigger in start-stop traffic too. Usually a harder hold on the brake pedal will shut it up. Also a clear correlation with some truck bumper types (pickups which are higher than me, and have that big trailer-hitch 'depression' in them seem to act like a parabolic dish and focus the radar return back on the sensor and trick it into thinking they're closer than they are).
I hadn't once considered there might be a problem with the unit, just that it was dumb software glitches triggering the sensors after a brief foot-off-brake creep forward made the car think I might be actually trying to park vs. just inching along a road. Guess using GPS correlation to decide when to actually 'care' what the sensor return is would be too dangerous, and conflict with the collision warning use of the unit too. But now you've got me wondering. I'm in a 2019, about 9000 miles right now.