It may happen that the message count bubble visible next to the Messages link on the top right after logging in does not reflect the number of unread messages but instead is a much large number. However, clicking on Messages revealed the correct number of unread messages.
This was an issue in TeleScope versions prior to 2020.5, due to which the number in the bubble was the count of all the messages in the user's inbox instead of it being the number of unread messages. This was fixed in TeleScope Standard 2020.5. It is recommended to upgrade to this or a later version. If your TeleScope installation has customizations or you're an OnDemand customer, please contact your Account Manager or support for further assistance with upgrading.
Once TeleScope is upgraded, the count displayed in the bubble should be the number of unread messages and wouldn't change after clicking on Messages.