Got 2nd IRS letter

I filed 2023 Feb 18 and got my refund Feb 26.   

I got a IRS letter 112C asking for info in March.  I sent back the info on April 2 to Fresno, CA.  Now on May 14 they sent me LTR 2645C from Philadelphia about "my inquiry of April 4" saying they need an additional 60 days to send a response.    Would that be for the same thing?  And would they have got my April 2 reply that fast?