Just did a quick test, folding up a piece of aluminum foil and placing it near the rear of the sensor will shield rear movement. Moving the foil to the side, attempting to shield movement from a 90deg angle, did not work. I did see a video where the signal was blocked from all directions by metal but not sure how thick it was.
I also have an HB100 doppler radar sensor with a range of 70ft, but requires an op-amp and I haven’t taken the time to solder it all up. I’ll do a post on it once its assembled and tested.