macOS Mojave Beach Ball when saving a file When I'm trying to save or select a file in a web browser, or any other application the beachball appears and the app hangs for ±30 seconds.

I didn't have this problem in High Sierra. Is it a common bug or specific to my hardware?
I have MacBook Pro Retina 15 2014
Found it. SMC reset didn't fix it. It's an iCloud issue. One solution is to remove the iCloud tab from the finder sidebar through Finder->Preferences->Sidebar.

It's not perfect, but at least productivity is back. I hope they will run an update that will solve this.

Peter