Both divorced parents, legally claiming 50% of Child Care Credit, seems to create a rejection status, happen for 2015 as well, but was resolved

[bwa · Accepted solution]

legally claiming 50% of Child Care Credit

They may have somehow forced 50% but they're not both claiming the credit legally unless.  To claim the credit you must be the custodial parent.  The custodial  parent is the parent the child lived with for more than 183 days in 2016.  One parent is the custodial parent, the other is not.  You can't split the child care credit by claiming that both parents are the custodial parent.