I do not believe this for one minute.
Actually, it can happen - briefly - to young children. If they’ve been separated for a while, at first they may not recognize their parent because their hair looks different or they are wearing different clothing. The problem resolves itself within 15 minutes after the child has a chance to hear their voice and talk to them.
I do.
Some goodly fraction of these kids barely met those "parents" before their real parents turned them over to be smuggled into America.
My three-year-old daughter once accompanied my wife (her mother) to my wife's homeland for four weeks. Upon returning, she at first acted as though she didn't recognize me. She was distant and cautious, and reluctant to speak English. So this is possible.
Nevertheless, there's one simple solution: Don't enter illegally!
Regards,