Chat Work Teams only to Personal Account and not to other Company

Hello All,

I have strange Issue in Microsoft Teams, i have a Tenant with Microsoft Teams, when i try to chat and search user from other company (like my work account) teams says "not possibile because organization is not configured to comunicate". I also check external access and all is ok.

If i try to chat with microsoft personal account problem is not present, is a limitation of my tenant ?

This is error:

This is a External Configuration

Regards,

Guido