HudMessage.SetDisplayTime() and both variants of HudMessage.Show() works just fine but HudMessage.Hide() doens’t do anything. Please Fix 
Updating. It still doesn’t work.
@Phantom_Fruity @2GHSamburskoy Thank you for your report! We would like to look into this further, would you be able to submit a bug report using the form available here? Fortnite Creative