The notice specified the correct Year-end.  My speculation is that due to the unusual amount of refund ($16K+) and loss (first loss in years mainly due to COVID), the refund processing was put aside by the handler and somehow the efiling was not registered on the IRS end.  I don't know whether this would cause the IL return NOT to be "forwarded" because the IL refund has not been received either. 

My impression is that even with efiling, tax returns still have to be processed by humans.  No?