How to add regular Microsoft account as guest user to our AAD based Yammer network in EU?

[jorrin1455]

Guest user was invited to SharePoint and added as guest user to our Azure tenant. Guest user has a Microsoft Outlook account without 365.

Our Yammer network is migrated and in Native Mode, situated in EU region.

When trying to invite the guest user I get an geo based error.
When trying to use the B2B collab option in the guest user profile in our Azure portal, to convert user it says "conversion failed".
When adding a Microsoft Business Standard license to the guest user, it still gives the geo based error.

When adding the user to the connected O365 group from the Office 365 Admin Center, it succesfully adds, but the user does not show up in the Yammer community.

Any thoughts on how we can succesfully invite guest users without exisiting AAD connected account?

[#2]

Guest Access in this way is not possible, yet. At the moment it's only possible to add guests from another AD-Tenant. It's something we want to do, too, but MS has not yet given any details if either allowing Guest Functionality for non-work/school-Acc. is in the making or even thought about.
The last Yammer AMA said, that this is an interesting Idea but Guest Access with non-M365 Accounts is not included in "this release" of the New Yammer.
Let's keep our Hopes up, that MS follows through with their Guest Logic as they did with Teams.