Subtitles out of sync when transcoding

[nothingveryobvious]

Hello. When I watch 4K media on my 1080p TV, it transcodes, which is great. However, when I seek, the subtitles are out of sync. On the iOS app on my profile, I enabled “Always burn in subtitle when transcoding.” Is that a client-specific setting, or should it apply on all clients? It doesn’t seem to be applying to my Android TV.

If that won’t work, what’s a solution other than having another 1080p copy of the media?

Thanks!