Please try the following:

Open your Windows Settings:

and choose Virus & Threat Protection.

then choose Virus & threat protection settings

Scroll down and in the  Controlled folder access section, click Manage Controlled folder access:

and make sure that Controlled folder access is OFF.

You also need to make sure that you are allowing apps to write to your Documents folder:

Right click on Window Icon on the task bar

Select Settings

In the search section on with Settings, type the word “Documents”

Then select “Allow access to documents library on this device”

Be sure have these settings ON

If this doesn’t help please enable your OneDrive

Right click on OneDrive (Taskbar)

Select More

Then select Settings

Select the Account tab

Then Choose folders

Be sure to have “Documents” checked off

Then select the  Auto Save tab

Then Update Folders

Then Start Auto Save

Be sure to have “Documents” checked off

Then Start Protection