I tried Google and another third party authenticator and the Friendly Name from tenant settings was imported correctly.
As another workaround you could try updating the Universal Login Page’s Multi-factor Page in the Dashboard. Under the Universal Login tab in the Dashboard and then the Multi-factor Authentication tab you can find the config for the page in question.
You could edit the line:
tenant: “{ userData.tenant }”,
to include the name you’re looking for hardcoded like
tenant: “Rabbet”,
Normally, that line should be using the friendly name. Could you take a look at the above and see if that changes how the name is shown in the Authenticator? The above should update those that are already set up as well once they’ve authenticated again with MFA.