Update: Apple has provided an "indefinite extension" to Apple ID login functionality, meaning that Apple users can continue to log in to Fortnite and other Epic games as they always have.

Epic claims this is because Apple has banned users from using Apple ID to sign onto any Epic Games accounts, with the ban to take effect "as soon as September 11, 2020".

Fortnite players won't be able to log in to Epic Games using Apple ID from Friday, in the latest development in the ongoing feud between the companies.