@PeterOz 

You gotta figure out that your sessions with the Internet are not route-able like this. There are two basic modes for the dual WAN. Policy routing and load balancing. Yet, they're not made for your purposes. Most companies got such dual-Wan routers with similar functions. I don't see any routers that can route/separate your upload and download from the WAN. 

Putting them in the bridge mode is a good idea. Yes, you won't have double NAT issues. But, you cannot do use one single line to handle all of your uploads and another line for all the downloads. Load balancing is about randomly balancing your throughput to both WANs. 

Hi @John1234 Thank you for that. My gut feeling was exactly what you have said. This saves me from going mad for hours running around in circles. Should I attempt to put both modems in bridge mode? I am researching now and I am not 100% sure yet if the Nighthawak will do bridge mode. Looking through the nat manual it does mention trying setting to PPoe Regards Peter

@PeterOz 

Right. Both in bridge mode. Nighthawk, I think I came across this model. It's a series of routers from netgear, right?

Getting them in bridge mode will avoid double NAT and a series of issues. 

Hi @John1234 nighthawk is a netgear device.(M2) From what I can see you cannot get bridge mode. I posted another question as I was not sure if I should continue here or not. Thank you for the advise and the follow up. https://community.tp-link.com/en/business/forum/topic/526848 Cheers PeterOz