iCloud will not synchronize after re-install Big Sur iMac

Hello.

My iMac was very very slow, so I had to re install completely.

Everything went oke and I have Big Sur installed after clean my HD.

But now I have one problem, iCloud will not synchronize after re-install Big Sur om my iMac.

When I want to stop it, it says it is busy synchronizing but it keeps hanging on a small amount. See picture.

I have also made a picture of the space I am using and there is enough.

What can I do to resolve this?