Map Network Drive on SharePoint Online Document Library

Standard

Login to SPO Site Using IE, Make sure keep me logged in is selected

Open IE -> Go to ‘Internet Options’
Select ‘Security’ tab -> Select ‘Internet’ Zone.
UnCheck the box for ‘Enable Protected Mode’

Make sure the ‘Web Client’ service is started on the client machine.
Open the SPO site -> go to the Document Library
Select ‘Open with Explorer’ [ Make sure this is working fine ] Copy the URL opened in explorer in the address bar
Delete IE Cache.
In IE ‘Trusted Sites’ zone add
https://*.lync.com
https://*.outlook.com
https://*.microsoftonline.com
https://*.sharepoint.com

Open Windows Explorer

Click On Map Network Drive

Paste the URL copied

Click Finish