prwnd Can you try disconnecting TV from mains for a minute and retrying?
Also see this post: How do I make additional buttons on my Panasonic remote work?Panasonic sending PVR button presses is a choice the TV makes (you can affect it with the magic button code)
and it may have just got disabled.
Please see my TV remote. I have a dedicated button (see picture) on the low right corner to control the "play, stop, pause" etc. buttons. With v7.95.2 and even with former Openelec everything went fine. I could even disable media buttons with that switch button. But with v7.95.3 i have problem with CEC itself. Non of the buttons are working.
Update: interesting anomaly. If i start to control OS with Yatse, after some minutes the remote starts to work. But is i change source (HDMI, TV, DVB-C) and go back again no response. And the game begins, i start to control with Yatse (Android) and after some minutes remote turns alive.
I made only one setup change, namely set the CEC preferences to default, but i think it has nothing to do with it.