User roles from bbpress cannot be deleted

Hi,

I have installed bbPress for testing purposes and then deactivated and deleted it. I can still see user roles from bbPress in the user roles list of Ultimate member: bbp_spectator, bbp_participant, bbp_moderator, bbp_keymaster and bbp_blocked.

I have tried to delete these roles with Ultimate Member. I have checked all of them and selected Delete on the top of the list. The page reloads, and I see the message “User role has been deleted successfully”. But the roles are not deleted and are still shown in the list.

Is there any possibility to delete these bbPress roles using Ultimate Member?

Thank you in advance!