Due to admin policy, you can't add external people to the channel

Copper Contributor
Hi all,
I have configured B2B Connect between my own tenant and another one, but when Im trying to add a external contact from the other tenant in a shared channel in teams, I get this message: Due to admin policy, you can't add external people to the channel

In B2B Configs, I already allowed all users/O365App from my and other tenant on both inbound and outbound settings.
My teams policy is enabled to Create Shared Channels | Invite External Users to Shared Channels | Join External Shared Channels. I have only this teams policy, and of course, its applied for all users in my tenant.
So, Im missing something? 
I believe if the settings are missing in other tenant, would be another error message instead of Due to admin policy, correct?
Thanks in advance
4 Replies
Did the other organization do the same? They need to allow their folks to either join any/all external shared channels or 'whitelist' your organization specifically.
The other organization is saying yes, they already configured as well, but thats the point:

Supposing my tenant settings are ok and their tenant settings are not ok, this error message should appears as well? Cause for my understading, this error message is only regarding my tenant policies.
How long ago did you configure it? And did you test it later as some policies may take a while before active.
9 days ago, and I tried to the same test right now and still fails.