It would seem unlikely that radars in various locations (planes, ships, and subs) would pick up the same noise at the same time, and the videos appear to show well-defined solid objects, not noise.
“the videos appear to show well-defined solid objects”
That’s not consistent with pilots’ descriptions. What they described was a sort of foggy enclosure or tic-tac shape with a rotating cube inside. From a greater distance maybe these resemble a solid object.