problem with Inviting people from specific domain to a Classroom

[Hadi-NDRS]

Hi everyone,
I created a classroom, and I want to invite somebody to my class from another domain. As an admin, I can do that without a problem, but I need help when I want to invite somebody with an account with the teacher's permission. The thing is, I can not invite a specific domain; that is weird because I can add another domain user to my account except for this specific domain.

I need to mention that I have this settings for my classrooms. 

Who can join classes in your domain

Any user

Which classes can users in your domain join

Any Google Workspace class

[Penelope · Accepted solution]

Class settings do need to work both ways meaning does this other domain allow cross-domain functionalities meaning just because this domain is on your allowlist does not mean the other domain has put you on their allowlist? I believe admins can check out the articles of https://support.google.com/edu/classroom/answer/6023715 and https://support.google.com/edu/classroom/answer/6173514. Also, if a domain is considered "untrusted" then Google can automatically make it so that teachers can't invite that domain per https://support.google.com/edu/classroom/answer/6237384.