M365 Security Groups not working to control access to SharePoint Sites in multiple tenants.

So it took some time to resolve with Microsoft (not a top priority ticket with them to be fair) and the issue has a simple resolution. Even though you have users as owners in the security group, they MUST ALSO BE MEMBERS of the same group in order to have access to whichever resource and membership level you're assigning them to. This seems counter-intuitive and problematic if you want the security group owners to be owners of said resource and the members to be at a different membership level. I'm not sure I fully understand or agree with this solution, but it works. It just means I have to consider how users are provisioned access in this manner.

Curious to hear your thoughts on this.