why my iphone se 2020 is freezing with black screen?

Why my iphone se 2020 is freezing with black screen and only option to work is to do hard reset (it is happen several time during last month when phone was in my pocket).

Is it a updates bug or I need to send it to repair?

If it is a bug when will we get a fix? or how to repair it if there is any possibility to do it myself?

Can someone help me in the topic?