Thanks to allot of information on these forums i managed to update boot loader and prepare an USB SSD (cheap china type: 32TB, micro USB to USB3 cable, connected to a USB3 port on RPI4B).
I gets stuck on the following error (xhc-cmd err 6 type 1) which i can not find/ solve :
It does not have an external power supply, but the red led is continiously on so i assume power supply is fine (i use Raspberry Pi 4 USB-C Power Supply / 3A , 15W). Also, when i just connect the SSD as external drive to the RPI4 , it has no problems.
Does anyone recognise what im doing wrong?