Check the captions during the live programme you actually want to follow. Write down the feed, programme time and player version. Try one known captioned on-demand title in the same app, then the broadcaster’s official live player if it is available in your region. The results help identify whether the difference follows the distributor, the app or the individual feed.
Look at the settings after a channel change and after reopening the app. Note whether the caption option itself is missing or visible with no words on screen. If words appear a few seconds late, time two lines approximately and include the programme context.
An example report is ‘Captions appeared on the 19:00 replay in both apps. During the live bulletin they appeared only in the broadcaster app. The television and network were the same.’ Add what you actually saw and keep account details private.