Most likely, when you copied your files, you also copied the desktop.ini file. This file contains the custom icon & languge-specific display name information used by system folders or any folder that's had a custom icon set.
So, in your MyDocs folder, Shift+right-click in the background and select Open PowerShell window here. Then copy & paste the following:
ri desktop.ini -force
(gi .).attributes -= 'ReadOnly'
The other possibility is that when moving, you inadvertendly made your MyDocs folder a system folder. To check, copy & psaate each of the following (one at a time) into the Address bar of Explorer to verify they still open the Documents folder:
shell:personal
shell:local documents
If either of those opens your MyDocs folder, you need to edit the path(s) found under:
HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders
Keith