Sad topic... kindergarten... son has been going to kindergarten for ov…

Sad topic... kindergarten... son has been going to kindergarten for over a year now, but I still feel like he doesn't like it, it's not his thing. We go to a good kindergarten, in a group of no more than 10 kids, we pick him up always in a good mood, but he goes there with huge sadness, sometimes they send videos and I see that he hasn't adapted yet and isn't eager to participate in games, etc. It's better to distance himself. He's become quite emotional and rather nervous now, first tries to release emotions, then tears come, very clingy to me, constantly wants to be on my arms, knees, sleep only in a hug or