iCloud items not syncing after clearing Mac caches

Hey there!

There should be no constant reason to delete your user Cache. It’s meant to speed up your Mac not slow it down. I do know sometimes it grows in size, but in those rare cases, it’s due to some application, or rogue process that causes this. In cases like that, it would be best to find the application, or process causing the issue, as deleting the cache won’t solve the problem. Hope that helps. Happy to lend any suggestions, however more information is needed as to the reason you need to keep deleting the cache. Thanks!

As you mentioned -

There should be no constant reason to delete your user Cache. It’s meant to speed up your Mac not slow it down.

Deleting contents from caches folder always increase the speed of Mac , it's done frequently Is it wise to clear system cache? - Apple Community

Please verify it with apple support senior care advisors .

Click on finder > take cursor on top menu bar Go > hold option key and click on library > delete the complete contents from folder Caches .

Restart the Mac the contents are recreated , you don't need to find any specific file relating iCloud .

This location is termed as used user library .

Also if there is major issue the files are not syncing with iCloud , create a new admin account in users and groups Change Users & Groups settings on Mac - Apple Support

Make sure iCloud Drive , desktops and documents box and inbuilt applications box is always checked , see this article Access iCloud Drive files from your iPhone and other devices - Apple Support

Deleting complete contents of cache is done , if in new admin account the iCloud Drive is not syncing then iCloud storage is full , downgrade the storage plan Access iCloud Drive files from your iPhone and other devices - Apple Support

If your files don't update to iCloud Drive

Check these things first:

• Make sure that you have enough iCloud storage. If you need more space in iCloud, you can buy more iCloud storage or free up space by deleting content.
• Sign in to iCloud on all of your devices and turn on iCloud Drive.
• Make sure that you have an active Internet connection on your Mac and on your iPhone, iPad, or iPod touch.
• Install the latest versions of Pages, Numbers, and Keynote. 
• Create a new document and save it to see if it uploads to iCloud. If it does, see if your other documents start uploading.

If you tried these steps and your files still don’t upload to iCloud, stay signed in to iCloud and save your updated files to a different folder on your Mac or PC. Then contact Apple Support for more help.

Note : most probably it seems Mac OS is corrupted .

Take suggestions from apple support .