Replace Router with Identical new Router, now Can't see Server websites inside LAN

Question

My webserver runs IIS 10 The Network shows as

I bought a new Linksys WRT3200ACM to replace the one that was starting to reboot a lot.

Same firmware version.

Saved router configuration from old working WRT3200ACM router to file.
Loaded that file on new WRT3200ACM.

Everything works BUT visibility of my web sites from inside the LAN.
It's like the server is double-NATted.

The network shows as "network 5". I'm thinking something with IIS is bound to "Network" and not "Network5" but I don't know how to fix this.

I put back my original WRT3200ACM and I can see all of my server's websites again. Swapp in the new WRT3200ACM and websites "took to long to load" and "can't reach (website URL)". After FIVE MINUTES, the site will suddenly appear. But I can't load a different site without the error.

Swapped back the original router and I can freely load any of my server's websites again.

The only thing I can thing of is that the Windows 10 server sees the new router as a new network. I discovered that was why drive shares were invisible too. Had to re enable network discovery to get shared drives back. However, there is no setting for IIS that I know of that enables visibility on the internal LAN after a network change.

With the new router, the server sees it as "Network 5". I assume the prior was Network 4. Is there something I have to do to Windows to make it IIS websites visible on the LAN? It can't be the router, as they are identical models running the same firmware version and configuration file.