Backstory (not sure if relevant):
I have recently noticed that during my initial load of the game (first load during the session) two music files are played at the same time: one of the current ambience my character is in and the other one being "Awake" ( i believe that's its name). I didn't pay too much attention to it at first thinking it's a random occurance, one-time (two-time?) bug and... well, it didn't bother me that much tbh. Once that "Awake" track's been played, the usual rotation would go unhindered (correct music files played at their corresponding locations and events).
Thinking about this matter while checking Nexus whether that mushroom house is back again, I decided to check the "Audio - Music" section of Nexus and installed a few music mods. I checked SSE High Quality Music, Unofficial High Definition Audio Project. Played a couple of days with it without noticing any difference (thoght my ears aren't qualified enough to). Then i decided to install a few music alterations (Music mods merged with correct installations). Now here's where the problem begins.
My main save files don't play correct musics when they should except for the initial load of the game. Not just the savefile, but only after I start Skyrim. If i load a save - it doesn't play either. Moreover, when i try to play certain music files via console (ex: musdungeonxx), nothing happens. HOWEVER if i start a new game or load a fresh character (level 2 cat) this issue is not present - everything works fine. I tried uninstalling/reinstalling various music mods, altering .ini, nothing happens. The world of my main character has become silent. It does play a few music files (that f***ing "Awake" and sometimes combat music (but not always).
I wonder what might be the cause of that because it's definitely not mod-related (my new games and my main have the same mod list and orders).
I also tried ReSaver, cleaned around 450 scripts, but the issue did not go.