You have Bitbucket connected to Vanta; however, a user's MFA status is misreported on Vanta. This happens because the user set up MFA on their Atlassian account instead of their Bitbucket account.
Go to your Bitbucket account
Click on the upper-right corner to expand your account options
Under Settings, select Personal settings
Under Security, choose Two-step verification
Turn on MFA
Bitbucket 2fa page
Atlassian 2fa page: