Hello, my name is Rusty. Sorry for the delay. Your remote has changed from DVD 1 to 3 by mistake. Panasonic makes the remotes changeable in case you have another player, so that each remote will only control one machine, instead of all of them.
On your remote, hold OK and 1 for more than 5 seconds. Keep an eye on the display. Press OK to confirm, and it will switch your remote back to DVD 1.