Why are you buying modem/router combo devices and attempting to use them as access points? why not get an access point or a simple router and set it up in access point mode? Those are better options and will cause less instability than trying to jury rig a combo device

plemans,
Thank you for your response.

“Why are you buying modem/router combo devices and attempting to use them as access points? Why not get an access point or a simple router and set it up in access point mode?”

First things first, I have purchased extenders, they did nothing. No visible difference in signals nor distance.
Ergo after several different attempts, with the same outcomes, I scrapped them entirely.

Research of access points forbade them as well because honestly, they rely on wireless signals. Best case scenario would be several wired points I believe. Mostly though, they are very costly. So costs, and the number of points necessary (was not yet determined), negated their use quite honestly.

Further research going forward I found online several videos of people taking old no longer used router and/or modem router combos using just the routers clearly, doing a/this conversion, to afford a make shift, “jury rig” (your words), signal extender/access point. Which I currently have 2 functioning points. One specifically, is an almost carbon (NVG443B) copy, of the one here I have posted this question about.

Now wireless signals are subject to many variables, do we agree? Whereas wire/wired points are a direct connect, the only variable being resistance in the wire itself. That labor is already provided, I did all that already, in cat 6. So I just need to access the router portion of this combo, change some protocols, replace a current 2.4G modem, with this one. Hoping that its dual band capabilities will function. It’s a trial sure, but worth it if it works.   

This combo I found on fleabay for $7.99 + shipping, my costs are negligable almost like I had “this no longer used old one” in the loft, money costs wise.
But it seems EVERY single IP address for this router, is a bust. It according to arris be 192.168.1.1, 192.168.0.1, the router shows 192.168.254.254, an online company out of ca, showed  172.16.1.10. Yet none provide access. My other arris (NVG443B), I changed to 192.168.1.100. It comes right up.

Now you have the whys, do you have any ideas I have not yet tried?
That was the question of the post quite honestly.

Its rare to get a combo device to function in access point mode. I’m impressed you’re getting some of them working at all. the modem side is usually locked down and many times, that bleeds over into the router side. I don’t know how to get your rigging to work as those aren’t standard usages and you’re mixing/matching random devices. 

If it was me and you have a hardwired connection, I’d switch to mesh system. many of them can use a wired backhaul between router/satellites. And they’ll allow wireless bandsteering, fast roaming, and be more stable. Please easier to setup and use. A bit more expensive than your fleabay but it’ll be easier, cause less issues whenever something reboots/power surges, or other issues crop up. I’ve been using mesh systems since they first came out and wouldn’t go back to a router-extender or router--access point setup. I’ve actually been looking at making the jump from consumer mesh systems to more business oriented 

plemans,
Thanks again for responding. Typically don’t do forums like this as many answers are over many of “our” (my) heads. First glance “mesh system” I’m intrigued but your right the costs are a bit overwhelming lol.
When I went into this I knew what I was lacking, but as to the ability to satisfy those needs were a mystery. I first tried it with the 2.4G Cisco sys modem only (as you suggested earlier), standard IP address bam I was right in changed what was necessary, voila satisfied that TV area, where TV streaming was a struggle. Worked well, but could have been much better. 
Fast forward I was finally granted permission to Starlink, way faster than frontier dsl. And it provided the necessary modem for the rear of my property ie: the NVG443B. 
At that point I bit the bullet bought a length of cat6, crawled in a very small difficult crawl area pulled Starlink hard wire to the office, then to the TV area. Ethernet plugged the wire bought the adapter from Musk (insanely priced), went to their wireless system to switch, hardwire to switch (tv area), now cisco modem for weather station, tablets, and wifi. Switch to TV now hardwired. 
Office hardwire thru UPC back to switch, switch to desktop, switch to switch (TV area), switch hardwire to (NVG443B) access point. Where the NVG443B is constantly over riding the stinky (Starlink), mesh router. I assume the 5G side, although IDK that as a fact.

I want to take advantage of the dual band capabilities of this NVG488BQ’s dual bands (if possible). 
I would like the front (TV) area, to have 2.4G for the weather station (which is its limitation). But also have the 5G for lappy’s & tablets. Which they seem to like better.
Which is currently not possible as I cannot access its internal settings gggrrrrr. 
At first glance mesh systems don’t qualify their Ghz, 2.4 (currently) in the TV area could be a minus, and everywhere else I’d be looking for max range so a plus.

Anyway I’m still stumped on how to access this combo router
 

Now however I pretty much only see “gateways”, and not router stand alone’s. Which I assume (I know, I know what assume implys), are the router side of the combo correct? 

There’s probably a reason it was the price it is. Those style of combo devices are sold to ISP’s and the ISP maintains and supports them. IF they worked well, super speedy, and easy to use, they’d be much more than $8 on fleabay. 

You can try factory resetting it and finding an access guide for it online. I’m not sure how much that’ll help you as you’re trying to add it as an access point. 

In regards to the mesh systems not having the capabilities you’re saying, I’ll be blunt. You’re wrong. 

Most are dual, triple band, and even some are quad band ones (like my current one). they ALL have 2.4ghz. They just integrate the bands all into a single ssid so the user doesn’t have to change devices between the bands. It lets lower bandwidth devices (like your IoT devices, weather stations) and keeps the higher bands for things like streaming, laptops, phones, etc that use more bandwidth. And it allows devices to move between its router and satellites as they move between the home. Or even just connect to a different access point because it might have better signal due to obstructions at a further device. Its more stable, tends to be faster, and provides better coverage. 

Again, you might get your system working just fine with enough time, googling, playing, but I’ll doubt it’ll be that smooth or effortless. 

Since you’re on starlink and probably limited to around that 100mbps (still solid speed) you don’t need a new system more oriented to hitting gigabit speds, some of the older AC mesh systems are pretty rock solid. I’ve used a netgear RBK43 or RBK53 with great success. Hardwired, they’re even better. Heck, if you’re using a wired backhaul, even the dual band systems perform pretty solid. A MK63 system (dual band) system is under $100 on there and with a wired backhaul, they’re fast. There’d bo no issue maxing out a 100mbps plan. wireless backhaul, it still probably could. 

Arris has the older W130 Or W133 systems that are pretty solid. I’ve used the W133 but at that time it had wired backhaul issues. Not sure if it still does or not. I posted about it on the forums but the post was closed without an answer. maybe @SURFboard_Big_Kahuna  knows if the wired backhaul is working or not on those systems. 

Sorry, most of my experience is with netgear devices as I test those a lot for beta testing. I’ve used the Arris W133 (quite a while ago) and currently have an Arris G54 (wouldn’t work for you) and the extender W6B kit. None of which would be the best for you. 

You can keep trying to rig something together if you’d like. I wouldn’t recommend it. You’ve paid a solid chunk of money to get starlink service. I’d outlay another smaller amount and get a decent system that provides good coverage, uses the latest standards, allows roaming, and just works. 

Connecting them to starlink can be a little more challenging as they have their own gateway. Usually you just connect them and then either put the new routers IP address into the starlink’s DMZ or you put the new router in access point mode. That leaves the starlink gateway managing it.