-Please send us the USB traces between the hub and PC for us to check the descriptor errors.
-Could you try connecting any other USB device such as another FTDI chip on the same port instead of the camera?
-Does the same configuration without the second hub work under Windows?
Thanks for your reply. Sorry, I should've mentioned that I can connect any other device I can think of - such as USB Drive, and it works. The camera also works fine with the hub under Windows. Also worth noting is that the Debian 9 Linux system is a Beaglebone Black SBC.
I have captures from linux usbmon. Let me know if you need some other kind of capture.
Not sure if this clears anything up, but it appears that Linux always manages to mount the camera if I reconnect the upstream connector after the camera is powered on (possible since the hub is self-powered). It almost always fails if I reconnect the downstream port to the camera and allow the camera to go through its normal boot process. Unfortunately, I can't just connect in that order since this goes in a piece of equipment.
As before, any combination of reconnecting works in Windows, and adding any cheap junk hub in between my hub and the camera makes it work fine regardless of the connection order.