iCloud Drive not syncing after macOS re-install

I used iCloud Drive to store all my files.

Due to various issues with my laptop I had to wipe the hard drive and re-install macOS on it (Catalina 10.15.1). I started with that installation completely from scratch, not restoring anything. But did of course sign in with the same Apple ID as my iCloud Drive.

But now the iCloud Drive folder is not downloading any of my files. I can see them all on icloud.com though.

How do I force macOS to synchronise the iCloud Drive folder?

Solution 1:

After several comments and clarifications, the iCloud sync process did eventually start. It took about 12 hours of leaving the laptop plugged-in and awake for the syncing to start.

Because there's no UI (this is supposed to be a background process), you really have no good way to measure the progress. Unfortunately, this has been a knock against iCloud for many years and Apple doesn't appear to be making any changes to improve in that area.