Many TVs and digital to analogue boxes (sometimes called DTAs) receive digital signals. These channels have sub-channels that use a dash "-" or a period "." like 4-2 and 56.2.
Many code sets do not have this signal because it is new, only in the last 2 years, so the code set that you first used to set up Flipper may not be working as expected.
Attached are the Flipper codes with this code. Just try other codes until you find a working code with the dash, or use the other solution, setting favorites in the