Inviting individual users from another org when "Check for Project on Authentication" is enabled?

Let's say I have two organizations,

A

A with and

B

B and they both have their own project (

projectA

projectA

projectA

projectA,

projectB

projectB

projectB

projectB) and an application (

appA,

appA,

appA,

appA,

appB

appB

appB

appB) . In

projectB

projectB

projectB

projectB I use

Check for Project on Authentication

Check for Project on Authentication

Check for Project on Authentication

Check for Project on Authentication setting. Now only users of org

B

B can access project

B

B (as intended).

How can I then allow some select individuals of organization

A

A to log in to

appB

appB

appB

appB? I've tried creating a role in

projectB

projectB

projectB

projectB and then authorizing users of

A

A, but I keep getting

Login not possible. The organization of the user must be granted to the project

Login not possible. The organization of the user must be granted to the project

Login not possible. The organization of the user must be granted to the project

Login not possible. The organization of the user must be granted to the project message.