can you please be more specific with "alerts assigned to their applications"?
I would still look for the issue in the configuration (scope) of the role. You need to make sure that the servers, from which the alerts are coming are in a group and that the role has permisssion on this particular group.
You need to also ensure that those users, which are configured within the role are not part of other roles, which might prevent alerts from displaying.
Can you please check this and post back.
(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)
Regards
Stoyan Chalakov