(This might not be the place for this).
I bought a Panasonic TX40EX700B from John Lewis a couple of months ago -
quite pleased with it. It is connected to the router by Ethernet and the
Netflix speed tester reports a download speed of over 60Mbs - we have a good
connection and that is the speed reported by my PC too. Netflix works well
and we can watch 4K TV.
If using the BBC iPlayer, it frequently stops and the whole set powers down,
turns off completely. If I restart, iPlayer offers to resume from that
point. If I watch the iPlayer via my YouView box this doesn't happen. I
can't work out how iPlayer gets to turn the set off.
Try asking on a Panasonic support forum?
Check if there is a firmware update for your model of TV.
@gspearson I'm afraid this is not something that we can help with as the service is not being provided by your BT TV subscription, you'd probably be best raising it with Panasonic and the iPlayer support.