I will PayPal F&F $25 to anyone who can help me figure this out. I have no idea what else to do. 

Here is the setup:

Network Gear:

OC200 V2 running on 5.7.6

ER 7206 v1.0 running on 1.3.0

TL-SG3452P v3.20 (48 Port POE Switch) running on 3.20.4

TL-SL2428P (24 Port POE Switch) v6.0 running on 6.0.4

4x EAP620 HD v3.0 running on 1.0.2

1x EAP610-Outdoor v1.0 running on 1.0.6

Internet Connection:

Primary WAN: (1 GBPS/1GBPS) AT&T Fiber (Switched Ethernet Network on Demand Product). Internet VLAN: 100, 802.1Q Checked, Internet VLAN Priority: 0, IPTV Settings On, Custom, IP-Phone 1100, IPTV: 1300 (AT&T instructions required Internet VLAN 100, 802.1Q checked, and IPTV Settings). Static IP

Secondary WAN (150 mbps/10 mbps): Optimum Cable/Coaxial with Static IP. 

Link Backup, 10:1 load balance (tried 1:1 too), Primary WAN with backup WAN. Online interval check: 3 minutes

LAN: 

192.168.0.1 - Management VLAN

10.0.20.1 - Secure VLAN

10.0.30.1 - Employee VLAN

10.0.40.1 - IOT VLAN

10.0.50.1 - Public WiFi VLAN

Disclaimer: I am not a network expert, but I have several OMADA deployments for simple network needs (such as homes and small businesses) without an issue. 

Issue: 

I set this up about 3 months ago without issue, the network was operating smoothly, no issues whatsoever. After updating the router to 1.3.0, all haites broke loose. I downgraded back to the previous version, still had the issue, reset everything on the network including the cloud controller to factory and reset up the network, issue still persistes. 

The Primary WAN will not work when setting up an Omada controller. I tried setting it up using the exact settings in standalone mode without the cloud controller and it worked for a few hours and as soon as a load was put on the network (everyone showing up to work the next morning), the connection failed. I reflashed the firmware on the cloud controller since I assumed if it was coming online using the standalone router instead of the cloud controller, there had to be a bug somewhere. I reset everything again and setup the Primary WAN and at last, it worked! No issues! I was able to get it online Saturday at 4 PM and it stayed online all weekend (monitored with the Cloud Controller). This morning (Monday) about 7:38 AM when everyone was logging on their computers, the primary WAN dropped. As if multiple packets of information was overloading the connection, although this is unlikely since it is a 1 GBPS connection. I am confident it's something within my settings not playing well well with the type of fiber connection we have (VLAN, IPTV, etc). I can disconnect the AT&T fiber physically from the WAN port and everything immediately comes online with the backup circuit (Coaxial/suddenlink) and works perfectly fine. I am just stumped. It worked fine for months and now it has stopped. AT&T sent a fiber tech out (this is not like the fiber you see in urban communities, this is a business grade project as you all probably know) and he said everything was testing perfectly and it had to be on our end. Our sales rep wants to switch us to a dedicated circuit setup isntead of this type of connection. 

I know it's something simple, and I am open to all suggestions. The person who gives me the right solution and it solves the problem I will gladly buy you lunch and a beer (PP F&F of $25). 

My email is: justinprater89 at outlook dot com if you want to reach out to me this way.