How can USB list become unaccessible to non root users at some point?

I'm using a Raspberry Pi4 device. We plug a USB HUB connected to 2 USB devices (a Fluigent pressure controller and a FTDI-based home made board controller). After booting, I run lsusb, it lists many devices (hubs, mouse, keyboard...). Then I plug my USB HUB. Now when I run lsusb, it only lists a single device "Linux foundation 2.0 root hub", all other devices disappeared. If I run sudo lsusb, the devices are all visible. What can lead to this? Non-root users should have access to USB enumeration. **Note:** I originally hit the problem by deploying some C++ code using library libusbp and got "libudev error -13" reported by libusbp. Then I found out that using sudo works and saw that lsusb reproduces the problem outside my progrem. Maybe this -13 error code can help.