I have a problem with ADUM4165 and ADUM4166 detecting high speed from some USB host ports. It seems that when it fails, the first K-chirp from the device on the downstream port is not copied to the host on the upstream port. In one case it fails with an 50 cm cable between the host port and ADUM4166, while it works with a short connection from the host port to ADUM4166.
Have anybody seen something like this case?