Voice not playing for some questions — previous question’s voice repeats instead

[reshmimahadevan]

Description of Bug :

For some questions, the voice for the current question does not play. Instead, the voice from the previous question is repeated. However, the text feedback (“Correct” / “Wrong”) still displays correctly on screen. This creates confusion since the spoken and displayed content do not match.

Steps to Reproduce:

1. Open the app and start the quiz section under Subtracting large Numbers
2. Listen to the question being read and answer it.
3. Proceed to the next question.
4. Observe the voice playback for the new question.
5. The current question is not played. Instead, the previous question’s voice repeats, while the text feedback (“Correct” / “Wrong”) appears correctly for the current question.

[Kebith]

This issue is related to https://github.com/oppia/lessons-team/issues/1888.