subtitles order of displa suddenly changed

[dionysis]

I was watching a film when, 40 minutes in, the bottom line of the subtitles was displayd as the top line and vice verca. When I rewinded, the same behavior continued in the part that I had already watched, although the first time around everything was ok. So this is not an issue of the srt file. Did I change something by mistake? Was it something in the srt file that caused the behavior retroactively?