Adjustment of Status - I-485

I applied for green card I-130 for my father who is outside USA and for my mother who is already in USA( I also submitted I-485 together and now she is waiting for an interview and for my surprise they didn't ask for RFE even though I submitted same birth certificate). But for my father they requested for RFE for additional evidence to show he is my father, the issue is my birth certificate shows wrong date which I didn't notice before sending I have Immunization record and Baptism and I also did DNA and the DNA center said they will send it to embassy for him to be collected there but they gave me invoice to send to USCIS with other evidences since the DNA can take time. My question is why are they asking for my dad and not my mom and do you think that is the reason why they are asking her for interview even though it is usually waived. Also, should I consult a lawyer before replaying the RFE? If I should explain why there is a wrong date in my birth certificate( Which clearly is a typo error). There is no way I can get new birth certificate due to corona? Please advise and thank you