FVS336G V3 : DualWAN not working when following guide

Hi Netgear Support and Enthusiasts

I have a FVS336G V3 as a DualWAN switch.

The main reason for this is, I do vanlife and have two 5g carriers for my internet service providers, since it takes 2 to cover the various deadzones. I am pretty much covered everywhere since i have both of these carriers.

According to the guides, it says i should use Round Robin when i am using both routers in tandem, for example in a location where i have access to both networks. if both carriers can get 100mbps in one location, using Round Robin will use both lines at 100mbps and attempt to send the same traffic across both networks to deliver my computer 200mbps speeds. If i set Weighted LB (Weighted Load Balancing) this should work when i have mixed network access, such as 50mbps for one carrier and 150mbps for the other carrier, Weighted LB will make that work at 200mbps combined, sending high traffic to the stronger network, and smaller packages through the weaker network.

Granted, i may be misunderstanding this a slight bit, where technically i think Round Robin is supposed to send the same traffic across both lines and only deliver the faster network on a per package basis, and not double speeds but increase speed and reliability.

Anyways, the short version of the issue is, Weighted LB gives me only the fastest speed of the slowest network, and Round Robin gives me a combined mixture of both networks.

Of course since i don't really have a "real" issue, since i've now got it set to Round Robin and the switch is doing what i want it to do, which is automatically delivering me the best speeds no matter where i am, i do still find this to be an issue for other members who may be only strictly following the guides. I was unable to get IPV6 working correctly, so i abandoned trying to get Failover set, since it was not giving me any working results, so i am on IPV4 only. I know it works - but also - 5G works best with IPV6, and is better for the entire ISP network as a whole, but i gotta work with what works also.

I am hoping someone can explain to me what's going on - am i wrong, am i misunderstanding these features, am i doing something wrong by using Round Robin instead of continuing to configure and reconfigure until it works right? Or is something wrong with the guides? Are the settings mislabeled?

I purchased one for myself and one for my physical property's business, where we also have 2 lines, but we use one line for backup when the other line goes down - which currently, is done with a physical selector switch to swap the main internet from one network to another in case of outages. I am concerned to set automatic failover settings, since Round Robin does work how i expect it to and deliver the necessary results, but it will be handling a much larger network in total there.

Please let me know what you think, and also, while i am doing this in a strict budget, please also advise any newer products that will provide the results we are looking for. I know the V3 will be capped at a certain linkspeed of 350mbps (combined up and down), and it would be even better to have something with a 1gbps linkspeed and proper IPV6 support (the router does see both networks in IPV6, but is unable to deliver that to my computer so i am just in IPV4, since that's what i need to use RR/WLB anyways).