Wrong sequence upgrade EX/CX. Is there a process to correct?

I have an Antipodes EX running on AMSv4.x. A few days ago I bought an Antipodes CX from a dealer who upgraded the unit to AMSv5.0.1. The devices are connected but both server and player are now on the CX and I can’t select the EX as player. On the userforum I read the sequence for upgrading is EX first. The old user interface for the EX does not allow me to upgrade to AMSv5x. What is the procedure from here?
Chain should be: Switch connected to CX through ethernet, ethernet cable between CX and EX, USB cable from EX to Ayre QB9 twenty.

If you have mis-matched software, then each unit must be managed individually, CX set to SERVER ONLY, EX set to PLAYER ONLY.
You can get in touch with your dealer to arrange software update.

Did you try myantipodes.com? I guess you would see both CX and EX. From there open EX and set as player only. CX is already available in your dashboard, so set this up as Server only.

Hope this helps.