imac 2017 slow start up after big sur upgrade

it takes 1 minute and 31 seconds for my imac to start op. After login it also takes approx 1 minute before displaying my home screen. Successive apps startup also takes too long.
Before the upgrade I never experienced this slow behavior.
Somebody with any suggestions?
I have same problem :-/
imac 2017 slow start up after big sur upgrade
 
 
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