400 Bad Request for IP address reservation on Nighthawk MR60

[mangoose]

I am trying to get my security cameras on reserved IP addresses, but my MR60 router will not allow me to reserve. I have a MR60 router with 3 different MS60 satellites wired to distant parts of the house. All cameras are wired to a PoE switch which is also wired to the router.

In Advanced>Setup>LAN Setup>Address Reservation, when I try to add, I get the following error:

400 Bad Request

This server does not support the operation requested by your client.

I have tried this on Chrome, Firefox, and Edge browsers. I have tried on 3 different PCs, I have confirmed my router and satellites are ALL running the most recent firmware, and I am at a loss. Any assistance is appreciated!

[antinode]

> In Advanced>Setup>LAN Setup>Address Reservation, when I try to add, I
> get the following error:
>
> 400 Bad Request

   "try to add" _what_, exactly?

   Generally, a HTTP error 400 suggests defective firmware and/or
corrupt settings.

> [...] ALL running the most recent firmware, [...]

   As always, an actual version number would be more useful than your
opinion of what's "most recent" today.  Also, "most recent" and "best"
are spelled differently for a reason.

[mangoose]

add an IP address reservation

firmware: Firmware Version V1.0.6.110_2.0.49

[antinode]

> add an IP address reservation

   Which part of "exactly" was unclear?  Is it a _valid_ LAN IP address?
I can't see it from here.

   I still suspect a firmware defect.  If you have some time to kill,
then you might try a settings reset and manual reconfiguration.  Or
loading a different/older firmware version.

[Yamimagic]

Shorten the Device name to 20 characters or less.  it seems that it happens on all routers.