Does listening to songs and religious lectures simultaneously make a person seem as if they do not understand, or a hypocrite?

Your colleagues' warning against listening to the Qur’an or religious lectures under the pretext of listening to music is a grave mistake. A believing person is enjoined to perform acts of obedience and avoid sins, even if they commit some transgressions. Performing acts of obedience, even minor ones, elevates a person's scale of good deeds on the Day of Judgment, and (Indeed, good deeds do away with ill deeds). Moreover, listening to the Qur’an and lectures might be a reason for turning away from listening to music. The coexistence of obedience and disobedience is not hypocrisy as long as the servant acknowledges their error and seeks Allah’s forgiveness. Therefore, strive to do good deeds and offer sincere repentance, and seek righteous companionship that will assist you in this.