I am performing a tenant-to-tenant SharePoint Online migration. I am migration one site collection at a time and all has gone fine until now. It appears I migrated a site collection over the target SPO Admin Center site. I didn't think that was possible but that's what I get for scripting the process :\
Anyway, the admin center now thinks it is a publishing page, complete with a 'Site Pages' library and a whole mess of other stuff that ought not be there.
When going to [tenant]-admin.sharepoint.com I am taken to the Welcome Page for the source site collection: [tenant]-admin.sharepoint.com/SitePages/Home.aspx
If I go directly to the ../_layouts/15/SiteCollections.aspx page, everything is there, so at least no baseline functionality is gone.
I was hoping I could just change the Welcome Page in site settings for the admin center but that was a bust. Any other ideas? I am hoping Microsoft support can just 'undo' this...but I'd rather fix it myself if I can.