upgrade big sur from catalina

[usernew]

I have iMac with catalina installed and want to upgrade to Big Sur and pressed upgrade now button and it started downloading but nothing happens after a long time 24/7. it does not finish to download. I have wifi stabil internet connection and does not receive any error messages.
I have enough space to install Big Sur.
Does anyone have this problem to?

 

[usernew]

This case is solved. It took me 2 days to finish downloading Big Sur before installing it.
I have relative fast internet so i can't figure out why.