DVB-T2 signal is sent by local antennas throughout the country, or many antennas that send signals in the region so that you can grab those channels from the air, a bit like GSM antennas. If you can receive a channel in Aachen on frequency X, it is possible that the same frequency in Berlin has Frequency Y and therefore no longer works, after this you have to search for channels again so that every channel that transmits the local antenna there is properly stored in the TV. .

It can therefore happen that the order of stored channels changes or that channels themselves disappear completely if they cannot be received in another location. This can happen, for example, when you are on the move from one place to another.