Internal Server Error when hostname used

Thanks for conducting the experiment.  My guess is that Netgear engineers attempted to resolve an issue that affected Orbi routers when in Access Point (AP) mode.  To wit:

• When in router mode, users could reach the web interface with a browser using any of the special URLs (routerlogin.com, routerlogin.net, orbilogin.com, orbilogin.net, etc.), but
• When in AP mode, the router did not perform DNS analysis and thus would forward connection attempts to those URLs "up the line" to the primary router, which would not be able to resolve them into IPs (because they are not really URLs).

I seem to recall posts on the forum from users unhappy that they had to enter the router IP address rather than the cool URL when in AP mode.  Netgear may have fixed that problem by having the AX series router examine URLs even when in AP mode.

What is not clear (to me) is whether the AX series:

• Examines http URLs (the "Host:" parameter) on every http connection attempt that passes through the router in AP mode, or
• Examines http URLs ("Host:" parameter) only when the http connection is directed at the IP address of the router in AP  mode.

I guess another experiment would be:

• Have no hosts entry for the Orbi router.
• Open a web browser to http://orbilogin.net from a device that is on the Orbi LAN (not on the WAN side of the Orbi)
• See if the router in AP mode pops up the web interface.

I'm still voting for "bug".