Frigate USB Coral external SSD


Using a PI4 with a external SSD and Frigate with a external USB Coral and reading the power requirements I see I should be using a external powered USB hub. Am I best to have both the SSD and USB Coral on the hub to USB 3.0 connector on the PI 4?

PI 4
A good quality 2.5A power supply can be used if downstream USB peripherals consume less than 500mA in total.

5 Power specifications
The USB Accelerator is powered by 5V from the USB interface through on-board power management chip (PMIC).
The device should be connected to a host computer with a USB cable that provides at least 500 mA at 5 V. Please note that when the device runs at maximum speed , it can draw a peak current of 900mA

Additionally, the USB Coral draws a considerable amount of power. If using any other USB devices such as an SSD, you will experience instability due to the Pi not providing enough power to USB devices. You will need to purchase an external USB hub with it’s own power supply

If I connect the Coral direct to the PI it works and triggers motion and detects person. If I connect via a powered USB hub the Frigate logs show TPU found ok

[2021-10-19 15:49:09] ws4py INFO : Using epoll
[2021-10-19 15:49:09] frigate.mqtt INFO : Turning on snapshots for Front_Dome_CCTV via mqtt
[2021-10-19 15:49:09] ws4py INFO : Using epoll
[2021-10-19 15:49:13] frigate.edgetpu INFO : TPU found

Now if I trigger motion ie a person I get this error

F driver/usb/] HandleQueuedBulkIn transfer in failed. Data loss: USB transfer error 6 [LibUsbDataInCallback]
Fatal Python error: Aborted

Thoughts USB hub is USB 3 powered with 2.5a 5v and connected to the PI 4 top blue USB connected with the lower USB 3.0 going to the external SSD drive

So I have this working with the Coral USB TPU on the PI USB 2.0 port rather that SSD and Coral on USB 3.0.

SSD/Coral both connected to the PI USB 3 works except power is not sufficient under load.
PI4 supplies downstream 500mA, SSD uses 297mA under load and Coral requires 500-900mA under load.

Added a 4 port USB powered hub and added the Coral with the hub connected to the PI USB 3 port, SSD to PI USB 3 port- result TPU detected but during motion - Data loss: USB transfer error 6.

Added a 4 port USB powered hub and added the Coral with the hub connected to the PI USB 2 port , SSD to PI USB 3 port - result TPU detected - motion detected records and works as expected.

So the question is powered hub is USB 3.0/3.1 and PI is USB 2.0/3.0, Coral is USB 3.0.
So why cant I connect the hub to PI USB 3.0 with SSD directly attached to PI or do I need to attached SSD and Coral to external hub then to PI USB 3.0 port?