Edit: It does look like a Plex Pass is required. I signed into the mobile app with a non-Plex Pass account and Adjust Subtitle Offset is not displayed / available.
Unsure if this is a bug or a lack of documentation.
Maybe somebody from Plex can weigh in with additional details.
AFAIK this is not a Plex Pass feature. I’ve Plex client v7.31.0 on Pixel 3a XL / Android 10.
Buried a few levels deep.
During playback:
- tap the screen to pull up on-screen controls.
- select vertical ellipsis in lower right corner
- select Playback Settings
- select Adjust Subtitle Offset
