✅Answer: Please pay attention to the following narrations:

1 عَنْ زُرَارَةَ وَ بُكَيْرٍ وَ الْفُضَيْلِ وَ مُحَمَّدِ بْنِ مُسْلِمٍ وَ الْعِجْلِيِّ كُلِّهِمْ عَنْ أَبِي جَعْفَرٍ وَ أَبِي عَبْدِ اللَّهِ أَنَّهُمَا قَالا فِي الرَّجُلِ يَكُونُ فِي بَعْضِ هَذِهِ الْأَهْوَاءِ الْحَرُورِيَّةِ- وَ الْمُرْجِئَةِ وَ الْعُثْمَانِيَّةِ وَ الْقَدَرِيَّةِ- ثُمَّ يَتُوبُ وَ يَعْرِفُ هَذَا الْأَمْرَ وَ يَحْسُنُ رَأْيُهُ أَ يُعِيدُ كُلَّ صَلَاةٍ صَلَّاهَا أَوْ صَوْمٍ أَوْ زَكَاةٍ أَوْ حَجٍّ أَوْ لَيْسَ عَلَيْهِ إِعَادَةُ شَيْ ءٍ مِنْ ذَلِكَ قَالَ لَيْسَ عَلَيْهِ إِعَادَةُ شَيْ ءٍ مِنْ ذَلِكَ غَيْرِ الزَّكَاةِ لَا بُدَّ أَنْ يُؤَدِّيَهَا لِأَنَّهُ وَضَعَ الزَّكَاةَ فِي غَيْرِ مَوْضِعِهَا وَ إِنَّمَا مَوْضِعُهَا أَهْلُ الْوَلَايَةِ

📚 Al-Kafi Vol. 3, p. 545

Translation: Imam Baqir and Imam Sadiq (peace be upon them both) were asked about a person who is in one of these persuasions—Hururi (Kharijites), Murji'ah, Uthmani, or Qadariyah—and then he repents and comes to know this matter (Shi'ism) and his opinion becomes good. Should he repeat every prayer he has performed, as well as fasting, zakat, and Hajj, or is the repetition of any of them not his responsibility? The Imam said: 'The repetition of anything is not his responsibility, except for zakat, which he must pay, for he placed the zakat in a place other than its proper one, and indeed, the proper place for zakat is the people of wilayah (guardianship).'

2 عَنِ ابْنِ أُذَيْنَةَ قَالَ: كَتَبَ إِلَيَّ أَبُو عَبْدِ اللَّهِ أَنَّ كُلَّ عَمَلٍ عَمِلَهُ النَّاصِبُ فِي حَالِ ضَلَالِهِ أَوْ حَالِ نَصْبِهِ ثُمَّ مَنَّ اللَّهُ عَلَيْهِ وَ عَرَّفَهُ هَذَا الْأَمْرَ فَإِنَّهُ يُؤْجَرُ عَلَيْهِ وَ يُكْتَبُ لَهُ إِلَّا الزَّكَاةَ فَإِنَّهُ يُعِيدُهَا لِأَنَّهُ وَضَعَهَا فِي غَيْرِ مَوْضِعِهَا وَ إِنَّمَا مَوْضِعُهَا أَهْلُ الْوَلَايَةِ وَ أَمَّا الصَّلَاةُ وَ الصَّوْمُ فَلَيْسَ عَلَيْهِ قَضَاؤُهُمَا.

📚 Al-Kafi Vol. 3, p. 546

Translation: Ibn Udhaynah said: 'Imam Sadiq (peace be upon him) wrote me a letter and said: 'Every deed that a Nasibi performs in his state of misguidance or enmity and Nasb, and then Allah favors him and makes him know this matter (our wilayah), he will be rewarded for his (previous) deeds and they will be written down for him, except for zakat, which he must perform again because he placed the zakat in a place other than its proper one, and indeed, the proper place for zakat is the people of wilayah. As for prayer and fasting, there is no making up for him.'

3 عَنْ عُمَرَ بْنِ أُذَيْنَةَ كَتَبْتُ إِلَى أَبِي عَبْدِ اللَّهِ أَسْأَلُهُ عَنْ رَجُلٍ حَجَّ وَ لَا يَدْرِي وَ لَا يَعْرِفُ هَذَا الْأَمْرَ ثُمَّ مَنَّ اللَّهُ عَلَيْهِ بِمَعْرِفَتِهِ وَ الدَّيْنُونَةِ بِهِ أَ عَلَيْهِ حَجَّةُ الْإِسْلَامِ قَالَ قَدْ قَضَى فَرِيضَةَ اللَّهِ وَ الْحَجُّ أَحَبُّ إِلَيَّ

📚 Al-Kafi Vol. 2, p. 429

Translation: Umar ibn Udhaynah said: 'I wrote to Imam Sadiq (peace be upon him) and asked him about a person who performs Hajj while he does not know or recognize this matter (Shi'ism), and then Allah favors him with the knowledge and belief in it; is the Hajjat al-Islam (i.e., the obligatory Hajj) his responsibility? The Imam said: 'He has performed the divine obligation, but if he performs Hajj, it is more beloved to me.'

4 أُذَيْنَةَ عَنْ بُرَيْدِ بْنِ مُعَاوِيَةَ الْعِجْلِيِّ قَالَ: سَأَلْتُ أَبَا عَبْدِ اللَّهِ.... قَالَ وَ سَأَلْتُهُ عَنْ رَجُلٍ حَجَّ وَ هُوَ فِي بَعْضِ هَذِهِ الْأَصْنَافِ مِنْ أَهْلِ الْقِبْلَةِ نَاصِبٍ مُتَدَيِّنٍ ثُمَّ مَنَّ اللَّهُ عَلَيْهِ فَعَرَفَ هَذَا الْأَمْرَ يَقْضِي حَجَّةَ الْإِسْلَامِ فَقَالَ يَقْضِي أَحَبُّ إِلَيَّ

📚 Al-Tahdhib Vol. 5, p. 9

Translation: Burayd said: 'I asked Imam Sadiq (peace be upon him) about a person who performs Hajj while being a devout Nasibi who belongs to one of the sects of the people of the Qibla (i.e., Muslims), and then Allah favors him and he comes to know this matter (Shi'ism); should he make up his obligatory Hajj?' The Imam said: 'If he makes it up, it is more beloved to me.'

✅From the above narrations, it is clear that Muslims from one of the misguided and deviant sects, upon converting to Shi'ism, do not need to repeat their prayers, fasting, and other deeds. However, they must repeat their zakat and give it to its rightful recipients. As for Hajj, although the Imams said there is no need to repeat it, they said: 'If he repeats the Hajj, it is more beloved to me.'