Fortnite Removing Support for Competitive Stretched Resolution on PC
Fortnite has announced that it will be locking the aspect ratio on PC to 16:9 in Arena and tournament playlists, however horizontal FOV will be unlocked in all playlists.
Vertical FOV will be locked in all playlists when using a custom resolution.
It was announced in the Competitive State of Development in April:
"In the near future, we will be updating how we handle custom resolutions on PC. When using a custom resolution, vertical FOV will be locked. Horizontal FOV will be unlocked in all modes, but in competitive playlists (e.g. Arena and in-game tournaments) we will be locking the aspect ratio to 16:9."