iCloud Drive Syncronization Error - Bird process

For over 6 months I am experiencing the problem that the icloud is not stopping to sync and not all files are synced successfully.

After 2 super bad and not helpful calls with the apple support team I want to try it with the community now.

The synchronization of my files is just not working. What I already tried:

1.) copy and backup all the files to just reset --> not working as I cant copy all the files because the bird process is using them (if i cancel the process i could lose data)

2.) just deactivate iCloud as the apple support team suggested --> i would possibly lose data. I told the apple support that they would be responsible and all of a sudden they told me I should not do it. Nevertheless, I tried and it did not even work as the process is not stoppable

3.) deactivatejust the syncronization of documents and desktop --> same response as point 2.

I then checked my console logs and found the following problems:

I would really appreciate any help or ideas on this. I am already going crazy with this issue.

Thanks in advance,

k