Group Restore doesn't restore SharePoint Site

[Anne O'Day]

Are there any known issues with the GUI process described in this document about restoring an Office 365 Group? I see that it was just updated on July 16, 2018, but we seem to be having some difficulty with the SharePoint portion of the restore process.  I have not tested the PowerShell steps.
https://support.office.com/en-us/article/restore-a-deleted-office-365-group-b7c66b59-657a-4e1a-8aa0-...

According to the article, when an Office 365 Group is restored from the Exchange Admin center, all of its related content is also restored such as the smtp address, aad security group, shared mailbox, sharepoint online team site, onenote notebook, planner, and Yammer if connected.

This started with a support ticket within our organization for a group deleted accidentally.  Six hours after restoring the "group" from the Exchange Admin center, the SharePoint Site Collection still was not restored.  I've now tested with five more groups in prod and demo tenants.  In all cases, the Group changes to Active in the Exchange admin center, and the clients can connect to the conversations, but the SharePoint site with contents does not automatically come back. 

An MS O365 Ambassador advised me to run Restore-SPODeletedSite which did recover the SharePoint site collection.  I was just worried that there may be more Group-to-SharePoint entanglements that are not fully restored, and I guess I will update this thread if I hear of any problems. 

Since Restore-SPODeletedSite does seem to have a "-NoWait" parameter, I was wondering if I just wasn't waiting long enough.  If this were on-prem, I'd probably go sniffing for a timer job to see if I could give the restore a little nudge forward.  But once I ran the Restore-SPODeletedSite, we got back our data very quickly, pretty much instantaneously available.  So at least there seems to be a resolution or workaround.  I've now waited several days for my test sites to come back in a demo tenant and they have not. 

Steps to reproduce
-Create Group from Outlook Client or Online  OR Create Team from Teams Application (for my testing, I tried each way and the outcomes were the same)
-Visit the SharePoint site for the associated Group or Team
-Delete the Site Collection (Gear icon in upper right > Site Information > Delete Site)
-The site collection will become unavailable (HTTP 404 not found), the Group will no longer be available in Outlook, and in the Exchange Admin Center the Group will change from "Active" to "Deleted"
-Go to the Exchange Admin Center, find the deleted group and hit Restore.  This step was first completed with an account that has the global admin role but then I also tested with an account that didn't have global admin but had EXO and SPO admin roles explicitly assigned.
-Wait. 
-Keep refreshing Browser to keep seeing HTTP 404 not found ... for a few days apparently ...

[#2]

AFAIK, the proper way to restore deleted Office 365 Groups is by means of PowerShell...I can understand that you would like ideally to have a way to restore a Group from the UI, but trying to do from the Exchange side sounds strange to me and that's the reason why the process is not working as you could expect

[#3]

It's just another example of the "loose coupling" between the different workloads that makes Groups tick. When you perform an action such as restore a Group, a "signal" is supposed to be sent to all the individual workloads, but as we have occasionally seen, this process is not as reliable as it should be. In turn, the instantaneous results we are expecting are replaced by longer wait period, until the async processes on the backend pick up the recovery operation (which can take 24h or more).

That said, it might also be some bigger issue on the backend, so open a support ticket just in case.