I can't change my mouse sensitivity on PS4. Also there is another bug that doesn't let me choose emotes in-game (I can only scroll through them) : r/FortNiteBR
Fortnite should consider adding an option to upload and save custom presets for settings such as key binds, mouse sensitivity, and controller settings. Here's my suggestion for the implementation of this feature. :
Fortnite - Page 19 - Supported Games - Mouse Sensitivity Community
Best Video Settings and my mouse settings (Fortnite) - SSLCK - YouTube
The Ultimate Fortnite Aiming Routine – Settings and Tracking - NOVOS Blog