I haven't seen any reports on what IRS is doing with RRC's.  If they are claimed in error, it's probably safe to assume that they will be disallowed.  If they are not claimed, I have my doubts about whether IRS will volunteer the information and send a math-error notice explaining the higher refund. 

It's one thing to tell clients to check their bank statements, but another to suggest they rummage through the dumpster to see if the debit card is still there.  

I haven't come across any inexplicable errors or omissions with the first $1,200 (or reduced amount based on either 2018 or 2019 AGI).  The second $600 was a real mess; the error rate will probably turn out to be more than 20%.  I tell clients not to be surprised if their refund is $600 less than what is shown on the return.  My clients are smart enough to understand that.  After all, they were smart enough to find me.