well thats correct as long as it wasnt unlocked with the proper fastboot command. And ADB is not fastboot, so for windows def update the bootloader (aka fastboot) driver.
Edit for reference, as it inlcudes a link to the e/OS forum as well 🇩🇪 FP4 - installation von e/OS stoppt bei step 9/24 - #3 by AnotherElk