Face ID doesn't work after iOS update, as well as other problems

Why this happen to me i just updated my phone with that security update after that startup my face id and brightness got dim and face id not working and heating issues are also been seemed after again I restart my phone my screen got frozen and apple logo been coming in a loop why this happening to me before this last time support made change my display just for mic why I'm asking this why this bug made me unsatisfied why your doing so ?

[Re-Titled by Moderator]