Thanks for the replies.
So, the mono mix sounds like a low bitrate mp3 because it was source from an mp3? 😃 Thanks for the link, I’ll get it asap.
There is a very strange thing with the “We seem to be made to suffer” shot - I tried it 3 times, and 3 times it behaved the same as I wrote. I closed PowerDVD and re-opened it. I played it again and the scene now plays correctly. Weird, but it was definitely a problem on my side.

So, after watching the whole Blu-ray I have to again say THANKS ! I loved it, I was actually excited during the trench battle sequence and DS destruction, which I found hard by watching the DVD/official BD versions