PotPlayer and madVR - Subtitles flicker when seeking

[Dark Magician]

In PotPlayer, when the video renderer is set to madVR, subtitles flicker when seeking.

Demonstration:

https://e.pcloud.link/publink/show?code=kZXKkZJ5K6wzDUVAh8uzaE6vCEmfIODk8X

In those videos, I am jumping frames. Subtitle flickering is not limited to jumping frames, but the flickering is exaggerated, making it more apparent and demonstrable. When I jump backward by seconds, sometimes subtitles that had appeared during normal playback do not appear after I had jump backward. In that case I can jump backward again, pause the video, and then play the video to get the subtitles to appear. I assume those problems are connected. Does anyone know what causes them?

It turns out that sometimes subtitles that had appeared during normal playback do not appear after I jump backward by seconds in MPC-BE, too.