Chat, Voice and Video calls with user with personal accounts (private users)

Hi
Happy new year to all of you.
Today i tried to use that new functionality that was implemented in december 2021 by Microsoft.
I should now be possible to chat and call with external users who have no organisation account and do not work in an other company if i am informed correctly.
I tried it and i can now chat between my private teams account and my organisational Teams account but i can not call or videocall between them. I find no policy where this is denied / defined. I checked our global meeting policy, call policy and teams policy. Does someone know what kind of policy / settings this is or is this right now not possible ?
Thank you for your help!