This occurs due to player stamina hitting zero, resulting in hp being lost. Below is the workaround for this in both C# and JavaScript.
C#
//Subscribe the Tick event
Events.Tick += Tick;
public void Tick(List<Events.TickNametagData> nametags)
{
RAGE.Game.Player.RestorePlayerStamina(1.0F);
}
JavaScript
mp.events.add('render', () => {
mp.game.player.restoreStamina(100);
});