Problem: When trying to connect to SharePoint Online site collection, I got this error message “Get-SPOSite The Site Tenant-URL is not properly formed.”
The solution is simple! Just remove the trailing “/” from the URL! E.g., In my case, instead of “https://crescent.sharepoint.com/sites/marketing/”, I had to remove the backslash “/ “after marketing.
So the right format of my site collection is: “https://crescent.sharepoint.com/sites/marketing“