After replacing the MCX8000 last week I thought that would solve the problem of not having a signal in my VDU display in Serato but, it didn’t so I created another volume on my MacBook and installed MOJAVE.
I then reinstalled SERATO DJ PRO and everything is working correctly. The VDU is correctly displaying the signal for recording. I also notice the controller is acting way less buggy. It is functioning the way it should!