Federal Return rejected due to a locked SSN

My mother's taxes were rejected because "The taxpayer's SSN has been locked by the Social Security Administration because their records show that it belongs to someone who is deceased."

This is correct.  My father passed in January of 2020.  The SSN entered in TurboTax is correct and, therefore, does not need to be "corrected" (Which is the only instruction TurboTax is giving me.)  What do I do?  I can call the SSA but I don't know why.  It doesn't sound like anything is wrong.  Does this mean my mother cannot file electronically?  (If so, how do we get our state electronic submission fee back?)