A. Try adjusting the speech settings in your iPhone. Go to Settings > Accessibility > Spoken Content and ensure that the options are set correctly. You can also try changing the voice or speed to see if that improves reliability.
B. If the text-to-speech function is still unreliable, consider using a third-party text-to-speech app that can read Pocket articles aloud. You can copy the text from Pocket and paste it into the other app.