Some players were unable to complete the weekly Fortnite Week 3 challenges; there are some issues with the floating rings. Epic Games has confirmed this problem and posted a message.
The Fortnite bug with the floating rings was added to the Trello board. It says the problem is only for Fortnite Mobile and PC.
What exactly is the problem?
Floating rings for floating ring challenges may be present but not visible on some platforms with lower settings.
Epic will investigate the error and will shortly post an update with the corresponding bug fixes.
Until then, Week 3 Weekly Challenges cannot be completed.