A badge that stays after you read everything is a count that has not refreshed. Brella shows three different badges, and each one clears in a different way.
The Networking tab badge
The number on Networking is the sum of unread chat messages and incoming meeting requests. Hidden chats are not counted.
Open Networking and select the Unread filter to see which chats still count.
Open each chat. Leaving the chat marks it as read.
Open Meeting requests and answer any pending request.
If the number stays, pull down on the Networking screen to refresh it, or open Account > App cache and select Clear app cache.
The Activity badge on the Home screen
The badge on the Activity tile counts the entries you have not opened on this device: announcements, meeting notifications and updates to your session registrations. Select Activity and close the sheet. Every item in the list is then marked as read on that device.
The app icon badge (mobile app)
Each push notification about a chat message, meeting reminder or meeting update sets the app icon badge to the number of your unread notifications on the server. The app has no control of its own for the badge, so the number changes the next time a notification arrives.
If the badge stays:
Open the chats and meeting requests that still count. Opening a chat marks its notifications as read on the server.
Wait for the next notification; it sets the badge to the current count.
To clear it right away, turn the badge setting for the app off and on again in your phone's notification settings.
Clearing the app cache does not change the app icon badge.
Notifications keep arriving on a device you no longer use
Select Account > Log out on that device. Logging out stops notifications to it until you sign in again.