USB FTDI device not detected

Hello everyone,
I try to connect a custom made FTDI device on the USB port of a Raspberry Pi Zero W (DietPi v9.1.1). The device is based on the FTDI FT230X. It works perfectly with Raspberry Pi OS and Windows. Under Raspberry Pi OS, a device /dev/ttyUSB0 is immediately created and the device appears with the lsusb command as:
Bus 001 Device 003: ID 0403:6015 Future Technology Devices International, Ltd Bridge(I2C/SPI/UART/FIFO)
None of that happens on DietPi. Nothing shows up with the lsusb command (and of course there is no /dev/ttyUSB0 device created). I have tried to install the FTDI D2XX driver and to declare the vendor and product ID of the device without success.
Strangely enough, a device based on the FT232X is perfectly recognized by DietPi (it has a different Poduct ID, 6001, but the same Vendor ID).
Any help on this would be appreciated.