@Fae It's consistent. The devices that are failing to obtain an IP address consistently fail, and the devices that work, consistently work. The TV connected for the first time with no issues.

I did find the logs, and it appears that my phone (the device I'm using the most to test with at the moment) does show up in the logs as attempting to get in, I'll post in a bit.

Edit: Log file. Here's the log, with the relevant entry for my phone (this is the MAC address for my Samsung phone.) It appears to be stuck in a loop where its asking for a discovery of the DHCP server, then the DHCP server offers up an IP address (seen in the log here) but the client never seems to return the request/ack session as shown in the diagram at the bottom? Again, I'm baffled as some clients (mentioned previously) work just fine, as to where these Android devices (and one iPhone version) don't. I tried a really old HTC phone I have laying around for giggles and it too could not get an IP address.

What's odd, is that it doesn't matter if this is using Pi-Hole or if its using the Omada/TP-link router built-in DHCP server. It still has the same issue. It happens whether its the EAP225, indoor or out - or the EAP235 wall units. 

Well, even better. Tonight my OC200 completely crashed, taking all the configuration with it. Thankfully I didn't change much of anything aside from the IP range but this is REALLY annoying. It actually appears as though my 2210MP crashed, taking the OC200 with it. Thankfully I haven't trusted any of this at all (which is really sad) to run my production network so I still have my existing network.

@Fae Thank you so much! I went around and reset all the devices and am now back at a totally default setup. All of the devices now have factory 192.168.0.x addresses; I've set everything at the most very basic setting to get WiFi up and running and now it appears that my phone will connect! Unfortunately I had to kill off my NAS server along with the Pi-Hole when resetting everything but again, at least I hadn't depended on this to be a production environment just yet. I set the few devices I was testing with back to the original network to at least keep me up and running. 

I'm honestly baffled with the 2210MP, I went into the data closet and found it had no power (which of course means that all the EAP's were down as well as the OC200) but when I plugged the OC200 into a different PoE switch (unmanaged) I have available, it wouldn't come back up. I wound up resetting it completely to get it back. What bothers me is that the version of firmware (latest) I have on the OC200 will not let me change the IP address manually of the 3428 nor the 2210. If I change the overall IP schema, it will of course pick up a DHCP address (at least, I hope) but I would prefer my infrastructure to have static IP's. This is something I have to downgrade to the previous version of the Omada controller software and really needs to be addressed in the next version.

A couple of notes: I took out the LACP links between the two switches (since all that was reset anyway) and I'm using the in-built DHCP. I'm going to go through my changes one at a time and see if I can figured out what breaks this. The LACP links (other than the NAS device, which supports LACP) were through SFP slots.

Again, thanks for helping me, hopefully support will be able to help me figure this one out and I'll post it up.