Expert Challenge: Unifi/Optik TV/Boost/Smart Security Configuration

[Grizsk]

Hi all, new to the forum and new to home networking beyond the admin panel of my modem. 

I recently acquired a UDM Pro from Ubiquiti, and after loads of trial and error finally settled on the 'port 1 bridge mode' option for a relatively stable configuration between my T3200M, UDM Pro, and Boost units. This is all well and good, but not what I had in mind. Obviously the goal is Unifi APs but I currently have a veritable house-load of the Arcadyan Boosts covering a 3200 square foot house and a suite, quite well despite their throughput limitations. 

When I picked up the UDM Pro I had done my research and was aware that to run my IPTV I'd need to rely on the Telus supplied modem. I don't mind, but in my head I was going to remove the SFP from the T3200M (which connects to a little Primex box, not sure if this is an ONT?) and stick it in the UDM Pro, then connect the modem after the UDM Pro as a sort of 'closed' network responsible only for the TV. I tried that after initial setup of the UDM, I connected the SFP module but wasn't really sure what I was doing to be honest. I then connected the T3200 via LAN on both units and didn't really see anything happening so I put the SFP back in the modem and moved to the bridge mode method with success. 

Whatever I did caused a bit of a ruckus with my Boosts and I ended up having to reconfigure them. During this process, I connected one to the UDM Pro directly as I'd read was possible in an r/Telus post and was delighted to see a whole bunch of clients show up in my Unifi Controller. This was great, I had wonderful visibility for a moment and then all of a sudden clients began disconnecting from the network (including my 6 AlarmCom cameras) and the Boost units went on the fritz for a second time. At this point I reconnected all Boosts to the Telus supplied TP-Link switch attached to my T300M, bridge mode engaged, reconfigure the Boosts and all is well. Now I can't see any clients on my UDM Pro and I'm sad.

Understanding that the above represents the extent of my knowledge of the situation, and that I have little to no idea what I'm doing, I wonder if anyone may confirm that the following is plausible and point me in the right direction:

- Fiber to the UDM Pro (makes sense to have the 'security appliance' at the front of the network, no?)

- T3200M 'after' the UDM Pro running all STBs

- Boost units connected to the UDM Pro (also handling the 'Smart Security')

Any ideas as to how I would go about setting this up would be a big help. I'm hoping its just an IP range or subnet mask issue (not that I know about those things) and somebody with knowledge far more robust than my own can chime in to give me a hand or serve me a reality check.

Thanks!