ISOUSB211: ISOUSB211 can't pass Eye-Diagram Test

Part Number: ISOUSB211

Tool/software:

Customer using ISOUSB211 as a USB isolator, it can't pass Eye-Diagram Test. It can pass the Eye Diagram  test without using ISOUSB211. Further testing revealed that there was a difference in the comparison between the end signal (EOP) and the Eye Diagram chart. How to solve this issue? Thanks.