Hi there, for your information, the AutoRecovery features only work when the Excel crashes unexpectedly and in other scenarios with files unsaved. You have saved your key Excel files well previously so the AutoRecovery feature didn't exert its function. Although it's tough to tell what's causing the Excel data loss, you can recover it with professional data recovery software.
You have saved the Excel file successfully so there were sectors written on your Mac, you can launch iBoysoft Data Recovery Software to search for lost data, which wins a high score and good reviews due to its excellence in disk scanning and data algorithms. Do not hesitate and use it to recover unsaved Excel files on Mac.