Android clients won't pick the correct subtitle

Appears to be addressed in a 9.7 beta release:

BETA:

  • Player: ensure correct external subtitle track is selected.

Unknown when 9.7 will go from beta to public release.

You can sideload a beta build if desired. Note that sideloaded apps do not update via the Google app store. You will need to delete & re-install the Google app store version to start receiving updates.

You can also join the beta program if desired.