I discovered strange problem with my setup, but perhaps it is broader issue. So to the point; apparently all media_players update media position attribute only on playback start/stop or at the beginning of new file playback. Then media player cards (build in media control card or custom mini media player card) takes start position and calculate actual media position based on start point + playback elapsed time. The problem is (at least for me), that every 30 seconds both media cards ‘resets’ the timer, so media playback progress jumps back to where it was at the beginning (to zero if it was new file or to start position for files that were resumed).
Is it something that only I observe in my system or broader issue? If it is my config, what might be wrong and how to remediate?