I wish I had seen this thread earlier. Maybe now I’m too late to the discussion to be of any help. I have dabbled a bit in genealogy but not so much recently. As I understand it, the SSDI records that you can access online for free haven’t been updated since about 2014. The SSA still maintains a more up-to-date database with the name ominous sounding name of The Death Master File, but now it’s subscription-only and annual cost is in the thousands of dollars. It takes some time after the death for the DMF to be updated, and I’m not sure how much time is typical.
The better subscription-based genealogy websites subscribe to the DMF and update their information at least monthly. You probably have free online access to ancestry.com even if you don’t know it. Many public libraries including the Chicago Public Library subscribe and typically you can access the site if you’re physically present at a library branch. Another option is to visit or call a FamilySearch Center. These are typically attached to an LDS (Mormon) Church but they are welcoming to non-LDS folks too. There are also affiliated public libraries that have access to some of the same datasets as the FamilySearch Centers, but I’m not sure if they have the DMF.