Vu+ MTSIF DVB-T2 dual tuner for Uno 4K Uno 4K SE Duo 4K Ultimo 4K

Hi, I have a problem with the tuner in question, in practice the digital terrestrial channels for a few days have been of very poor quality: The signal drops quickly and the channels are very difficult to see, then I made a test by recording a channel from T2 I can't not to watch another one first since it's a dual, that is, you watch one channel while you film another. Now I'm wondering, do you think it's broken? Let me start by saying that I bought it a year ago, thanks to whoever will give me a answer....