Group-connected SharePoint site was restored after the group was deleted

[TobiasAT]

Hello, I'm not sure if this post is a topic for SharePoint or Office Groups.

I know a deleted Office group can be restored for 30 days. The SharePoint site for 93 days via the SharePoint recycle bin. Now we have a situation that we restored a site after 70 days, and yes, the connected group was already deleted. I found no description from Microsoft about this case. We saw the site has issues related to the missing group. What are the known or recommended steps in such cases? Can we recreate a new, empty group for the SharePoint site? In a normal case it's possible to connect a new group to an existing, not group-connected SharePoint team site. But this option is not available for a restored team site. 

Thanks for some information.

[#2]

As update, I asked MS support the same question. They know the situation and confirmed the difference between group and SharePoint recycle bins, but for now they have no plans to fix the situation in the next time.

• It is not possible to add a new, empty group to a restored team site. The method described here is not possible if a site was restored from the SharePoint recycle bin. 
• It's not recommended to use a restored group-connected team site without a group (e.g. if a site was restored after 30 days). Users should migrate their content to a new team site. 
• Using retention policies to hold deleted groups for 93 days is a recommendation. In these cases admins should exclude the option for SharePoint sites, else the SharePoint site has a retention policy of 93 days + 93 days.