INDICATION YOU MIGHT NEED A MoCA FILTER

You could possibly see one of several different messages on your TV screen when adding/using STBs (e.g. PXD01ANI) the most common being XRE 10007.  Working with the 'assistant' or customer support, you may go be tempted to go down the same 'rabbit hole' I did - I RECOMMEND THAT YOU DO NOT !

The PXD01ANI (or any box that works with the Voice Remote XR15) communicates with your main STB, like the PX022ANx, using MoCA.  This PXD01ANI will 'look' for all other MoCA boxes within reach, and without a MoCA filter on the cable feed for your home, may find STBs in other condos/homes.  The main STB (e.g. PX022ANx) does NOT have to use MoCA to work but responds to requests from PXD01ANIs that do.

Fortunately there is a simple way to determine if there are other MoCA cable boxes trying to communicate with your main STB, even before adding a PXD01ANI.  

Enter the technician diagnostic screens by on your main STB:

Hold down EXIT key until LIVE appears on TV 
then very quickly press DWN ARROW, DWN ARROW and  2

From the MoCA Diagnostics screen, displaying the MoCA mesh transmission rate should show only data for the devices you have.  In my case, with a MoCA filter in place; a PX022ANx and two PXD01ANIs I see data for devices 0,1 and 2 but BEFORE resolution of the problem I saw 5 or sometimes 6 - a CLEAR indication of the need for a MoCA filter. On yours it depends how many PXD01ANI in total you have in addition to the PX022ANx.

NOTE: The non zero numbers displayed will change, but the number of rows/columns showing data should be stable.

ALSO, if you already have PXD01ANIs, you can also enter the technician diagnostic screens and, in addition to the MoCA mesh, you can see how many MoCA devices you have talking to the STB you are on currently.  In my case, with a total of 3 boxes, each PXD01ANI should show ONLY two others connected.  Before installation of the MoCA filter I saw 4 or 5 NOT just the address of my PX022ANx and the other PXD01ANI.

My recommendation is that BEFORE adding any STB to your main box is to enter MoCA diagnostics and see if there is an indication on the MoCA mesh screen of other devices attempting to communicate with the PX022ANx. If so, request an appointment to install a MoCA filter for your home BEFORE adding a PXD01ANI.