Calling the below returns a list of followed sites for the signed in user.
https://graph.microsoft.com/v1.0/me/followedSites

However the 'displayName' attribute returned above is incorrect - it is the site 'name' which is returned.
See below correct displayName when querying /sites/ using ID
https://graph.microsoft.com/v1.0/sites/[id]

Steps to reproduce:
Create a SharePoint site with 'name A'
'Follow' the site
Change the SharePoint site display name to 'name B'
Observe /me/sites/[id] show displayName as 'name B'
Observe /me/followedSites show displayName as 'name A'