Has the security implementation changed in Miro? recently one guest (within the organization, same domain email) without license was able to see all the boards, even though they had link for one board only.
Answered
Board visibility to guest invited to a particular board
Best answer by Robert Johnson
Is the board in question located within a Free Plan team? If so:

Example:

Now any user with a Miro account who clicks on the link generated by the button would land on the Miro board AND would also automatically be added as a Member of the Free Plan team:

When I change the permissions to the following:

Then the board’s Share settings changes to the following:
This topic has been closed for comments
Enter your E-mail address. We'll send you an e-mail with instructions to reset your password.