The patent fee reduction filing system has been qualified, but the fee reduction is not allowed after the patent application is submitted. The reason is that the fee reduction filing is unqualified. What is the reason?
When did you file the patent? Because now the filing opinions of 217 have started, did you slow down the filing in 216?
Did you submit the paper version of the slow down filing materials to the Patent Office?
Did you pass the filing before submitting the patent fee?
If not, you can only call the Patent Office ~ ~ I hope it will help you.