Girls, who have experienced it - the child is sleeping only 20 minutes…

Girls, who have experienced it - the child is sleeping only 20 minutes during the day, both naps. He used to sleep an hour and a half, at least 40 minutes, and now he sleeps only 20 minutes and that's all, we are energetic and cheerful ? Is this a growth spurt or a yearly regression or something else? Has anyone had this? How long did it normalize?