Why my videos look blurry(they also jam, stop in middle of recordings when phone would even reboot itself and so on)

because they modified inside of hostel yet another new telephone I purchased. Even video converter programs were modified to produce video files 4 x times larger than should be. But this was all organised by Polish police who also refuses to investigate own crime.
One would have to be super wealthy to satisfy Polish police appetites as they do nothing but crime.