I found solution for that:
Install this app: https://play.google.com/store/apps/details?id=com.aboutmycode.betteropenwith&hl=ru
Then I selected "video stream" and put VRTV as favorite.
After that I was able to see it in the list of players when doing "Open As".
I'm not sure what does this app is doing... but it really works. I think this app is just resets some configurations for prefered apps and it helps.