Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Hi Edwin Derry,
I go through the post carefully, basically, we may remove contents in Viva learning by delete documents in source folder, and managed permission of source folder, as you can see from the link: Add SharePoint as a learning content source for Microsoft Viva Learning | Microsoft Docs
If the contents still remains for a long time after you tried to delete them, I would suggest you create a support ticket on the issue from Microsoft admin center>Support.(if you are not admin in your tenant, please contact admin to create support ticket. For more info on Get support - Microsoft 365 admin | Microsoft Docs), agents on server side have more resource and tools to troubleshooting the issue further and fix it, thanks for your patience and understanding!
Best Regards,
Clark