Contents of Documents folder disappear

Hey there, Adrian,

Thanks for visiting the Apple Support Communities to get help with Finder. If you're certain you aren't syncing with iCloud, let's check next to see what the overall storage of your Mac currently looks like: See used and available storage space on your Mac - Apple Support. Make sure you are not running low on storage.

If you are, use Free up storage space on your Mac - Apple Support to make some space, and see if the issue persists.

Don't hesitate to respond back if you need more help.

1 - Restart in Safe Mode. This will perform a Disk Repair, clear cache files and only load Apple Software, extensions and fonts. The boot up will be slow and can take some time - Normal.

2 - Does the issue present in this mode ?

3 - Sometimes a Safe Boot followed by a Normal Boot will just put things right.

4 - If not - there could be something in the main User Account playing up. To further isolate this - Set up users, guests, and groups on Mac. Then log out of the Main User account and log into the dummy account and test again if the issue persists.

5 - If the issue is present in the dummy account - then, this appears to be a System Wide issue on the computer.

6 - If after performing each of the above steps is the order that have been presents  and still have issues - please advise for possible further assistance.

Understand, we are all working Remotely from all around the world. 

Therefore, we do not have the On-Hands experience the User ( you ) has with this computer.

The next best thing for us to having a semi - actual On-Hand experience  with this computer is to follow the steps below

Download the Application Etrecheck directly from the Developer. 

The application is free or paid from added features. 

It will take a Snap Shot -  both the hardware and software.

 The Report will Not Reveal Any Personal Information. 

Post back the Full Report - copy and paste - using the Additional Text Icon ( 3rd Icon to last )

We can have a look at the report for possible issues and may have possible suggestions to resolve the issues.

Any Third Party Applications that will interfere with the normal operation of the OS,  is an invitation for disaster and comprising the Operating System

Certain Applications maybe available on the Apple Apps Store - this only means the Developer is prepared to pay Apple a portion on each sale. What the Application may do to the computer is up to the User to check this out before purchase

Any of the below should be removed as per Developers Instructions

This will include CleanMyMac , This will include BitDefender , 

This will included Norton Antivirus , Sophos Av Software

Intego AntiVirus, McAfee, MacKeeper, Avast AntiVirus

Ad Guard, Webroot , ESET

The The Built in Security  is all that is required.

I see nothing in the supplied report above to account for this infrequent behaviours - Documents Content disappearing and re-appearing

Unless the Documents folder is house on an External Drive which is dismounting and remounting.

Based upon your description " I have since learned that I just have to Restart and everything will return. " this sounds like a likely possibility

EDITED - spelling error

You are welcome 🇨🇦

Do come back to the Apple Support Communities ( ASC )  in the future, if / or when additional questions may arise

Welcome and do keep us posted on the hopefully positive progress

Thank you the Report 👍

I will dissect it in detail and get back to you asap