update firmware; do a factory reset. are there too many devices connected to the wireless at the same time? heavy burden connectivity will easily break down the connection. Try reduce number of...

there an on/off switch, no Save button

based on the FAQ http://www.tp-link.com/en/faq-923.html, packet will be sent to a particular pc instead of all pcs in the subnet, so it seems to be unicast

How do you tell it is restarting？ Have a try to unplug it then replug it back. Plug into a different wall socket. Reset it by pressing the reset hole for longer time with power on. If all these steps...

Before you connected the wifi extender to the RV, have you paired the base unit and extender unit. Make sure the second lights are on on both units when they are in the same room first. Then relocate...

Is you issue resolved now?