Script error to enter pwndfu mode

[SakuraKyuo]

The exploit is failing and the device (iPhone 6S Plus) isn't entering pwned DFU mode.

Output:

Found: CPID:8000 CPRV:20 CPFM:03 SCEP:01 BDID:02 ECID:00000000000000 IBFL:1C SRTG:[iBoot-2234.0.0.3.3] ERROR: Exploit failed. Device did not enter pwned DFU

And sometimes returns this:

Found: CPID:8000 CPRV:20 CPFM:03 SCEP:01 BDID:02 ECID:000007772B951EA8 IBFL:1C SRTG:[iBoot-2234.0.0.3.3] Traceback (most recent call last): File "./ipwndfu", line 75, in <module> checkm8.exploit_a8_a9() File "/home/sakura/ipwndfuA9/checkm8.py", line 528, in exploit_a8_a9 stall(device) File "/home/sakura/ipwndfuA9/checkm8.py", line 118, in stall def stall(device): libusb1_async_ctrl_transfer(device, 0x80, 6, 0x304, 0x40A, 'A' * 0xC0, 0.00001) File "/home/sakura/ipwndfuA9/checkm8.py", line 45, in libusb1_async_ctrl_transfer assert usb.backend.libusb1._lib.libusb_cancel_transfer(transfer_ptr) == 0 AssertionError

I tried to do something to solve it, but no work
I run it on Ubuntu 20.04