Fastboot error with rb3

Hi everyone,

I am trying to open fastboot mode. I typed adb reboot bootloader command. After that I can see this logs from com port :

EFI Total : 800 ms
POST Time      [ 3217] OS Loader
Loader Build Info: Dec 21 2020 22:30:13
VB: RWDeviceState: Succeed using devinfo!
Press <Down> to enter fastboot, <Up> to enter recovery, or <ESC> to enter EmergencyDLOAD
Recovery command: 32 bootonce-bootloader
KeyPress:0, BootReason:2
Fastboot=1, Recovery:0
GetVmData: making ScmCall to get HypInfo
GetVmData: No Vm data present! Status = (0x3)
VM Hyp calls not present
Launching fastboot
Fastboot Build Info: Dec 21 2020 22:30:12
qusb2_1: hstx: 7
PLL1 locked: 5
usb_lane: 1
Fastboot: Initializing...
Fastboot: Processing commands
Fastboot Action (Press <Right> to select): SAT
Dev_EventError: EfiUsbMsgBusEventResume not allowed in state DEV_STATE_DEFAULT_ADDRESSED
Handling Cmd: getvar:product
DwcUpdateURB:Trb: TRB ring of EpIndex 2 is full
UsbfnDwcSubmitUrbNode: UpdateUrb Failed: 0x8000000B
UsbfnDwcTransfer: Failed to submit transfer
UsbDeviceSend: Failed to submit data transfer: Device Error
Error, failed to handle USB event
Exit key detection timer
Press any key to shutdown

now fastboot devices command returns nothing. why is that ?