See the reason for the differences in "number of conversations" between the Conversation Management and the Analytics section of the University Dashboard below:

The Conversation Management section looks at the date when a conversation dialogue was first opened between an Ambassador and the Prospective Student.

The Number of Conversations graph in Analytics looks at each unique message's Sent date, thus the count here will be higher. This graph tracks the number of conversations that have been initiated by Prospective Students, so this could include conversations that have yet to be responded to from a Student Ambassador.