B0197 USB device recognition problem

  1. Where did you get the camera module(s)?

  2. Model number of the product(s)?

  3. What hardware/platform were you working on?

Linux version 5.10.17-v8+ ([email protected]) (aarch64-linux-gnu-gcc-8 (Ubuntu/Linaro 8.4.0-3ubuntu1) 8.4.0, GNU ld (GNU Binutils for Ubuntu) 2.34) #1421 SMP PREEMPT Thu May 27 14:01:37 BST 2021

  1. Instructions you have followed. (link/manual/etc.)

  2. Problems you were having?

  3. The dmesg log from your hardware?

  4. Troubleshooting attempts you’ve made?

  5. What help do you need?

I installed B0197 on about 400 raspberry pi 4s in remote locations.
And I am taking snapshots every 10 minutes using fswebcam.
However, there is a problem with about 40 devices.

Problem 1. If the USB is not found and a reboot is attempted, the problem is solved, but it reoccurs after 1-2 days,
Problem 2. USB is found, but recording is not taken with the response /dev/video0: No such file or directory, so turning the service off and on or attempting a reboot improves it, but it reoccurs after 1-2 days.

I visited the site and replaced the Raspberry Pi, but it happened again,
We are testing for 2 days by replacing the camera module and cable.

What kind of tests can I do to isolate the cause?
HW ?
SW ?