I am just now noticing this on several returns.  One common thread I have noticed is all the ones rejected for it were once dependents of their parents in the prior year.  In 2021, they are filing on their own for the first time.  Not sure if this has anything to do with it.  I am following up with them to see if they have 1095-A forms issued.  ProSeries will not let you input a 1095-A with zeroes on it.