#1 ISOUSB211 Can,t Work

Hello, I am very happy to find this open source solution for ISOUSB211. I also implemented the content, but I found that it does not seem to work. If you use a USB tester, you will find the upstream part, such as "Mobile phone-USBC cable-USB Tester-USBC cable-ISOUSB211 test board", D+D-voltage is 3.2999。 if you use a USB tester, you will find the downstream part, such as "Mobile phone-USB C cable-ISOUSB211 test board-USB cable C-USB test device", the D+D- voltage will swing between 3.299 or 0.3-3.299. After connecting the USB DAC, it will still be the same situation. However, the only modification I made to this open source solution was to change the USBA female socket to a USBC female socket, and the measured voltages of the ISOUSB211 upstream and downstream chips were normal. Therefore, I would like to ask if there is any operation or other circumstances by the original author that would cause this situation? In addition, in order to avoid impedance problems, I also tried to directly connect the UD+, UD-, DD+, and DD- of ISOUSB211 with flying wires, but I still achieved the same result.