Fairphone 4 stuck in fastboot mode after /e/OS install – not detected by Minimal ADB

Ok, that’s current Android SDK platform tools in use then, as it should be, not a hopelessly outdated Minimal ADB and Fastboot command.
It was just a thought.

In case you want to continue on Windows, seeing you had mentioned Minimal ADB and Fastboot as well as Zadig, which sounds like all in all it could result in a proper mess … I would suggest a cleanup/repair next …

… and let Windows install the necessary drivers automatically then, don’t try to outsmart it with third party tools from the start.