I actually suspect the problem with the radar is actually with the housing. I had my radar replaced because I kept getting the malfunction message and couldn't use propilot. The radar was replaced but not the radar housing. The issue continued when I got the car back after a few days. We called Nissan and they looked into it and told us that they should have replaced the radar and the housing as one unit, but instead they had replaced only the radar and reused the old housing.
They ordered the all-in-one unit and installed it. I suspect that the original housing allowed for moisture / dew to get inside and that affected the performance of the radar. They must have redesigned the housing, or a gasket in order to prevent this from happening. At least that is my guess based on my experience.
Although, this morning the ABS light was blinking, but it was very cold this morning and perhaps it was because there was frost / dew on the front windshield covering the sensor above the rear-view mirror. However, it never gave me the yellow triangle with the malfunction message in the display. It stopped blinking after about 10 minutes, perhaps after the frost / dew evaporated?
I will keep an eye on it and post more if anything changes.