Fairphone 4 fastboot devices doesn't work in fastboot mode [SOLVED]

[talkingCarbonAtoms]

I just got my Fairphone 4 yesterday and I wanted to flash it with /e/ OS image so I followed the install tutorial Install /e/ on a Fairphone FP4 - “FP4”
I enabled developers options, unlocked oem and allowed usb debugging. I installed android sdk followwing these instruction Installing adb and fastboot on a Linux PC.
I can see my device using

adb devices

and I can reboot the phone in bootloader mode with

adb reboot bootloader

When in bootloader, I see my devices serial number and device state is locked,however, when I type

fastboot devices

I get nothing. When I try

fastboot flashing unlock

I get “waiting for any device”

If I go to recovery mode and fastboot devices, I see my device and when I do “fastboot flashing unlock” I get the error “flashing unlock unrecognized command”.

Both my adb and fastboot version is 33.0.1.8253317. I am using Ubuntu 20.04. Anyone has got any idea how to resolve this?

EDIT:
I managed to solve this just by connecting the phone to a different USB slot and then fastboot seems to work.

[AlphaElwedritsch]

this has already happened to some here and has been addressed several times.
A change of the USB port or the cable often solves the problem.

[Minelava]

I had the same Problem. As this was the first post I found while searching for a solution, I will post what worked for me. It seems as if people already encountered this problem with the fairphone 3.

I installed the Universal ADB Drivers and sure enough, the device was immediately recognized as fairphone 4 as soon as I connected it. But it turned out that the device needs a different set of drivers while in FastBoot Mode.

After I booted into bootloader mode, I had to check the devicemanager again and update the driver, as detailed in Step 5 of this guide.

I found the solution in this post.