Mysql UTC format works for "SELECT" but NOT for "UPDATE"

Question

This is the columns "created_at" datatime

And I can query "created_at" with a UTC time

But alert "Incorrect datatime value" while "UPDATE"

I don't know, but for UPDATE command, I have to use a 'YYYY-MM-DD HH:MM:SS' format, and it works

But still makes no sense to me,

I believe the UTC is more accurate, and if "SELECT" could recognize UTC, why not "UPDATE"?