Single witness server for multiple db mirroring session

My current witness server is already configured as witness server for db mirroring sessipon in preview env in port 5025 now when I'm trying to use the same witness server as witness servers for prod env under port 5025 I get the following error:Msg 7862, Level 16, State 1, Line 1
An endpoint of the requested type already exists. Only one endpoint of this type is supported. Use ALTER ENDPOINT or DROP the existing endpoint and execute the CREATE ENDPOINT statement.
Msg 7807, Level 16, State 1, Line 1
An error ('0x800700b7') occurred while attempting to register the endpoint 'AAA_Mirroring_Prod'.
Command I'm using to create endpoint, this is at the witness server.
CREATE ENDPOINT [AAA_Mirroring_Prod]
AUTHORIZATION [XXXaaaa]
STATE=STARTED
AS TCP (LISTENER_PORT = 5024, LISTENER_IP = ALL)
FOR DATA_MIRRORING (ROLE = WITNESS, AUTHENTICATION = WINDOWS NEGOTIATE
, ENCRYPTION = REQUIRED ALGORITHM RC4)
I'm using unique EndPoint names .
Pleaes help!!!!!

The way I read Book Online (Article "Database Mirroring Witness"), a server can be the witness for multiple mirroring sessions. I would expect that a single TCP port number could be associated with a single mirror session (principal/mirror pair). Can you select a different port number for the second mirror session ?

Looks like we can have multiple endpoints per SQL instance BUT of one type only, which means we can have only one endpoint per SQL instance for db mirroring, port differentiation does not matter. However, we can use the same endpoint for witnessing multiple db mirroring session. I ended up using same endpoint for my preview and prod db mirroring session.