iCloud Drive does not sync for a particular account

Dear,

Recently, I bought a MacBook Pro 13 and I am having the problem below.

Symptom: iCloud Drive does not sync for my account, but it works well for other devices(iPhone, iPad, Window lab-top)

What I did

1. When I looked for cases which is similar to these symptom in the web, there were some cases. But there was not solution with the cases.
2. According to the recommendation of the apple staff, I waited for an indexing process which is conducted in a new device for 3 days. But the process was not a cause of my case.
3. When I logged in iCloud service with another account, iCloud drive worked well. I confirmed this with my several accounts.
4. I had just files of 15 GB in iCloud Drive. After backup the files, I removed all files in iCloud Drive of the account. I thought there could be a problem with my files. But it is still.
5. When I login the account with other device(my wife's MacBook), the problem was still.
6. Of course, I followed the instructions in apple website with regard to iCloud Drive. But they didn't work.

Please

I suspect this problem is with Catalina OS. This can be considered a data server or software problem and should be resolved quickly. I really hope this problem could be solved.

Thanks