Easy Installer cannot connect to FP5 in bootloader step

• /e/OS version: latest
• Device model(s): FP5
• Impacted Application: Easy Installer
• Used computer OS: Windows 10
• Used browser: Microsoft EDGE Version 135.0.3179.54 (Offizielles Build) (64-Bit)

The problem

When I use the Easy Installer
And I double checked the USB debugging option to be on
And I double checked the OEM unlock to be on 
And I double checked the default USB configuration to be File Transfer
And the Fairphone 5 got recognized in Step "Device detection"
And the /e/OS Downloading is finished
Then the device reboots into bootloader screen
When I click "connect"
Then the device is not found

Error in Browser after losing focus to popup

Error on step: connect-bootloader Cannot execute command connect bootloader The device is not connected Failed to connect: Cannot connect Bootloader Proposal: Check connection and that no other program is using the phone and retry.

More information

Reading through the manual installation guide I found the hint: "The FP5 comes with an anti-rollback feature"

I checked for the security patch version. It is different from the version of the official OS there /e/OS build : T official (Security patch: 2025-01-05)

The device shows

• Android version 14
• Android security update February 5, 2025

This could be a reason for the bootloader not working