This instance has no database configured for database mirroring (4341639)

• when selecting Server1 the principal database is mirrored to Server2 successfully.

• when selecting Server2 the message 'This instance has no database configured for database mirroring" is displayed.

DBSS - Database Mirroring Role requires user account with with sysadmin role.

1. Connect to SQLServer using  as Foglight user, run the following query:
   select * from sys.database_mirroring
   or
   select s.name , m.* from sys.database_mirroring m, sys.databases s where m.database_id = s.database_id
   
2. Check IsMirroring metric based on sys.database_mirroring if there is a non-NULL values on a mirror
   e.g check the columns  mirroring_guid, m.mirroring_state, mirroring_state_desc 
   
3. Navigate to Security | Logins |   check if the sysadmin server role is given.
   
4. Restart DBSS agent

Further details about required permissions are here.