Note that the normal process of refetching the HLS playlist won't cause automatic media selection to run. Manual media selection should not be changed by automatic media selection unless AVPlayerItem's selectMediaOptionAutomaticallyInMediaSelectionGroup: is called. Legible criteria affects how subtitles are selected. However, the criteria only applies when automatic media selection is enabled and automatic media selection has determined that the criteria needs to be applied. Related to question #1, manual selection disables automatic media selection, so specifying criteria when in manual mode won't change the subtitle selection. Also, the global MACaptionAppearanceDisplayType affects how subtitles are chosen. If you want to turn on subtitles and supply criteria, you should also check/set MACaptionAppearanceDisplayType. See https://developer.apple.com/documentation/mediaaccessibility/macaptionappearancedisplaytype "Auto" has been removed from the UI, although automatic media selection still happens automatically by default. Note that in most cases, an audible language mismatch will result in subtitles if there is a matching non-forced subtitle language available. Regarding issue #1, which seems to be the focus of this post, Could you please file a Feedback Assistant and upload a sysdiagnose when you saw the issue, along with the time of the issue, and post the FB # here?