2020 Tax Return Status

I completed and submitted a 2020 Tax Return electronically for my mother-in-law who passed away on 3/16/2021.  I received an E-file Status response from TurboTax that the IRS Accepted the return on 3/26/2021.  There was a refund due.  It's been almost 7 weeks since filing and still we still have not received a refund.  Using the IRS "Where's My Refund" tool, it reports "You may not have entered your information correctly. Please verify your personal tax data and try again."  I've checked and re-checked the data (SSN, Filing Status, and Refund Amount) and it is correct. When I contact the IRS to inquire if they have received the submission, they will not talk to me because I'm not the taxpayer.  I've submitted a "Form 56" which is supposed to allow the IRS to share info from my filing.  Regardless of my status, why am I getting the response from the IRS tool I described above??  If I resubmit a new return, will this just complicate things further??