src/ui/battle_ui.rs

@@ -49,3 +49,9 @@ pub fn spawn_battle_ui(mut commands: Commands, request: Res<PendingMatch>, fight
 
     Ok(())
 }
+
+pub fn cleanup_battle_ui(mut commands: Commands, battle_ui: Query<Entity, With<BattleUI>>) {
+    for entity in battle_ui {
+        commands.entity(entity).despawn();
+    }
+}

src/ui/mod.rs

@@ -12,6 +12,7 @@ pub struct InGameUIPlugin;
 impl Plugin for InGameUIPlugin {
     fn build(&self, app: &mut App) {
         app.add_systems(OnEnter(AppState::InMatch), battle_ui::spawn_battle_ui)
+            .add_systems(OnExit(AppState::InMatch), battle_ui::cleanup_battle_ui)
             .add_systems(PostUpdate, fighter_info::update_fighter_info_damage);
     }
 }