JellyCon playback sometimes fails when using softsubtitles

[killemov]

When I start a certain video file with softsubs it seams like the player just times out. When using no subs or when hardsubbing while transcoding (Allow subtitle extraction on the fly: OFF) playback starts almost immediately.

To Reproduce
JellyCon -> Jellyfin Libraries -> TV -> TV - Next Up -> Episode -> Select Subtitle Stream
Click on '2 - eng' -> ... waiting ... -> Playback fails

Expected behavior
Playback starts

Systems

• OS: Raspbian on PI2B
• Jellyfin Version: 10.8.13 (Official Docker image on Debian 12 host.)
• Kodi Version: 19.4.0
• Addon Version: 0.8.0

Additional context
HTTPS is OFF, due to my PI2B being too slow to handle it.