The remote control does not switch NC+ channels. I have to artificially enter the decoder menu.

Hello, some time ago I changed the decoder to 4K ULTRABOX+ from Cyfra+. Everything worked fine for a few months, recently I can`t change channels normally using the Prog+/- buttons. I.e. I can, but first I have to artificially enter the decoder menu and then go back to artificially call up the channel change bar at the bottom and only then can I change channels with the remote control (Prog+/-). Has anyone encountered such a problem? Is there some strange function/lock enabled?

The remote control has no lock. It can only control turning off the TV and adjusting its volume. However, they behave strangely when the batteries run out Press the TV button, the red LED will light up. And now press any key. When the diode dims to zero, the batteries need to be replaced. Even though e.g. the volume works.

Maybe the remote control is so defective that it doesn't work, I had such a case once.