Bought my m21 in August 2020, now iam facing the issue of sudden freezing and restarting again and again.. this occurs after my software update.. please do the needful

I bought my Samsung m21 in August 2020, kow iam facing issues as it's freezes and restarts again and again... even though auto restart feature is off...This problem occurs only after I updated the software... iam getting frusted by this... please do ...