Glitches when playing a local file that's being appended to when cache is enabled

Important Information

Provide following Information:

• mpv version: 0.33.0
• Platform and Version: Windows 10
• Source of the mpv binary: Sourceforge

If you're not using git master or the latest release, update.
Releases are listed here: https://github.com/mpv-player/mpv/releases

Reproduction steps

Play a partially download .ts video with --cache=yes.
Skip towards the end
Resume the download before it reaches the end

There's no problem with the cache off but then I can't see how far behind I am on live broadcasts. It's also fine if the download doesn't pause for more than a couple of seconds. I am also aware of the tail -f -c +0 trick but that has caveats such as not being able to skip back beyond the cache unless I close then reopen the file.

Expected behavior

It should continue playing with no glitches

Actual behavior

The video glitches on the point where it was resumed and get errors in the console
[ffmpeg/video] h264: error while decoding MB 56 32, bytestream -17

Reproduce with a partially downloaded .ts video, --cache=yes, and a pause before resuming the download; compare behavior with caching disabled and inspect the reported H.264 decoding error. Done means playback resumes without glitches when the appended file continues downloading.