HDTV 5.1/Original 5.1

[John W]

Hi! Recording from one TV network, I noticed that 5.1 on the TV channel is a bit strange. Audio on the side channels (1-2, 5-6) becomes quieter depending on amplitude variation of the central (3) channel. And this only happens on TV, there's no this thing in the original 5.1 which can be ripped for example from DVD. But the problem is that episodes of the series with 5.1 are released only on DVD, which you have to wait for months after airing, which doesn't come out very often and covers not all episodes that were released. Thus, the only permanent source of 5.1 sound is TV. But this 5.1 sounds very crumpled, besides, if you compare with DVD, there is some kind of compression, and it seems to me that in 5.1 on TV there are hissing noises (especially this can be heard on 5-6 channels).
I don't even know exactly what this is related to. I thought it was related to amplitude, but now I think it can also be related to frequency or, I don't know, to something else. I thought this could be some kind of modulation, but I don't know. Sorry, I'm not very good at this all. Maybe I'm thinking wrong and my way of thinking may seem wrong.
So does anyone know how to fix this problem? I leave 2 samples: one is from TV and one is from DVD (original). And you can compare.
Thank you!




P.S. If you wonder, the show is SpongeBob and the network is Nickelodeon