Check the status screen of the CPOTS card and make sure all 4 ports are provisioned the same. Check wiring of the shelf. If it's a 23" chassis it will use seperate amphenol connections for each port. The amphenol connection labeled T/R is for port 1, T1/R1 is port 2, E/SG is port 3 and M/SB is port 4. All 4 amphenol connections will need to be wired out.