QRMP GSTR3B Auto Population

Sahil Shah (26 Points)

16 April 2021  
I have filed IFF facilty for Jan & Feb 21 correctly.
Also filed GSTR 1 for Jan to March 21 quarter correctly.
Now, while filing GSTR 3B for Jan to March 21 quarter, the auto-populated 3B is not matching with what I have filed. Auto populated figures are less than what should have been.

Should I change the auto populated data in 3B to correct figures?
Also, what could be the reason for such mismatch?