It's not possible to do what you are trying to do. You cannot have two routers on the same LAN sharing the same subnet. You can set the modem to bridge mode and use your own router if that has better...

A portable router should to work. You should look for something that offers a builtin hotspot mode to get around any mac address limits the hotel might choose to enforce....

HW V1 FW 3.17.0 Build 20161008 Rel.64225n Tried numerous time servers and always a problem reconnecting to the web interface after the router updated the time on its own. Since disabling nntp support...

UPNP is inherently insecure and you should not be using it. Your C9 is apparntly protecting you from yourself.

Si el enrutador no se enciende, está roto y necesita comprar uno nuevo.

Useless subject line btw... How many walls are between you and the router when you are 12 m away? Might they be made of concrete?