I understand that changes have been made to limit group finder for those without an authenticator, and that is not a bug. However, it is stated by Blizzard that those players can still create a group, just not write custom text. That is fine, however, the title is considered custom text. It appears you are unable to create any group unless, for example, you have a key for a Mythic dungeon where the title autopopulates.
If a player without an authenticator / text notifications (due to circumstances of not having a mobile phone), attempts to create an M0 group, they are unable to do so, because you can’t create a group without a title and you can’t write in a title without an authenticator. It seems that if it was intended that those without an authenticator are still able to use the group finder, that selecting “Halls of Atonement” and “Mythic” from the dropdowns, it should autopopulate that information into the title. That may be seen as a suggestion, which I will also provide via different channels, but overall I don’t think it is working as intended based on the responses that those players are still able to make groups, despite adding this restriction. Or the support text needs to be updated with the types of groups that are permitted to be made.
“Since patch 9.1.5, only accounts that have been secured with a Battle.net Authenticator and Phone Notifications can add custom text to Group Finder listings. If you don’t have an Authenticator or Phone Notifications, you can use the Group Finder, but you will not be able to write custom text on your listing.”