Agree w/ Tom D. that the reporting by broker was correct and the taxpayer response should be just to reduce the taxable amount with suitable coding notes: QCD/Rollover.
Sounds like the consequence of violating the 1 rollover/12 mo rule would be to make the entire transaction taxable and the part that was rolled over an excess contribution. https://www.irs.gov/retirement-plans/ira-one-rollover-per-year-rule
If you don’t get a response by Alan S. here, you might try posting in the retirement forum . Now I’m feeling better about handling the RMDs manually….because of the QCD issue. Long term tho it would be better if the broker took that into account as well as any other withdrawals so certainly an issue to feedback to them so they can improve their process.