Can't connect MBL to new wireless router when connected into my Modem

I have a new router (Netgear Nighthawk R8000). I have my MBL live plugged in my Modem Router (which does not have sufficient wifi range as the router).

The Modem has IP and Subnet 192.168.0.1 / 255.255.255.0 and DHCP is enabled.
The router has IP and Subnet 192.168.1.1 / 255.255.255.0 and is wired into the modem via ethernet cable into the internet(yellow) port of the Router.
The MBL has IP 192.168.0.4

I have tried connecting the Router to the Modem via one of the Router’s LAN ports but this delivers a very unstable internet connection.

Could any one give me advice as to how to change the MBL settings without upsetting the Modem or Router stable internet settings I have at the moment. I have tried a soft reset on the MBL, however this does not change the fact that I unable to connect to the MBL via WIFI from the Router.

I also wish to continue to access the MBL via the Modem (ethernet to Desktop) and would also like to now add access via WIFI to the Router.

As I am not an IT expert any advice would be appreciated.
Thanks

I’m puzzled by your description. If your modem has DHCP enabled then it must also have a built-in router. I don’t think its DHCP server does anything outside of the 192.168.0.0 subnet. Do you have anything other than your routed connected to that LAN segment? (That may not be important to your problem, but I can tell I don’t understand your configuration.)

You say your MBL has IP addr 192.168.0.4. Is that a static address was that just the last address assigned to it when it lived on the 192.168.0.0 subnet? If it is a static addr you are going to have to change that for it to live on the 192.168.1.0 subnet. I think the soft reset you tried was supposed to undo a static address and revert the MBL to a DHCP-supplied address. That should have allowed the router to be accessible by other devices on your LAN - whether wired or wireless - if you have your MBL plugged into the router.

Does your router see your MBL? (It will now be a 192.169.1.n address.) If so, can you ping its address from your computer(S)? If so, your MBL is physically reachable but not accessible by the networking software.

What operating system do you have on your computer(s)? I donn’t know anything about Macs, but Windows 10 makes the computer “undiscoverable” when a new router is detected. That makes NAS devices on the LAN inaccessible. If that is the case you have to tell Windows that your network interface (the Ethernet adapted or wireless adapter) in on a “private” network.

Hi thanks
My modem is a modem router and I have 2 switches connected to the Modem Router’s LAN ports that are connected via datahub to my wired ethernet ports around my house including the nighthawk router.

I have also tried connecting the MBL to the Nighthawk Router’s LAN ports rather than the Modem Router’s LAN ports and doing a soft reset of the MBL and then I can access the MBL on the Nighthawk Router’s WIFI but then I lose access to the MBL on the wired ethernet ports connected to my Modem Router.

I would like to access the MBL via the Modem Router’s LAN ports wired to my ethernet datapoints and also the Nighthawk Router’s WIFI. The modem router is in the datahub in the garage while the Nighthawk Router is in the Study connected via ethernet data point.

thanks

Just a couple of other points to note
I am using Windows 10 on desktop PC and Laptops.
DHCP is enabled on both the Modem Router and Nighthawk Router

The Modem Router is a Netgear VEGN6210
The Router is Netgear Nighthawk R8000

If I disable DHCP on the Modem Router will I still pick up the LAN ports on the Modem Router?

Thanks again