I'm new as Linux user and I'm also new as a member of this forum so please forgive me stupid questions.

Yesterday audio stopped working (from nothing) at my notebook (Kubuntu 18.04 LTS with TLP). When I started a movie it plays few seconds and then audio mutes. On Windows everything works well (i have dual boot). I was trying to fix it by reloading alsa or reinstalling pulse audio. Now speakers work when I'm testing them in system settings but I lost almost all interface elements from system settings which are connected to audio and I still don't have sound while playing videos and so on. For example I don't have a speaker icon in right-bottom corner of the screen and cannot re-add it.

[this part SOLVED] I want to restore all audio options to my system interface at first. Is here anyone who know how to do this?

[EDIT] I fixed problem with no elements in interface - i have to install plasma-pa. But not I have still the same problem as before. While starting video sound is at first corrupted and after few secunds it smoothly mutes.

What can I do with it?

Which application do you use to play a movie?