ok i think it works now

source/funkin/editors/charter/Charter.hx

@@ -378,7 +378,7 @@ class Charter extends UIState {
 		};
 		uiGroup.add(scrollBar);
 
-		songPosInfo = new UIText(FlxG.width - 30 - 400, scrollBar.y + 10, 400, "00:00\nBeat: 0\nStep: 0\nMeasure: 0");
+		songPosInfo = new UIText(FlxG.width - 30 - 400, scrollBar.y + 10, 400, "00:00\nBeat: 0\nStep: 0\nMeasure: 0\nBPM: 0");
 		songPosInfo.alignment = RIGHT;
 		uiGroup.add(songPosInfo);
 
@@ -403,7 +403,6 @@ class Charter extends UIState {
 		addEventSpr.alpha = 0;
 		addEventSpr.cameras = [charterCamera];
 
-
 		// adds grid and notes so that they're ALWAYS behind the UI
 		add(gridBackdrop);
 		add(sectionSeparator);
@@ -851,7 +850,8 @@ class Charter extends UIState {
 		songPosInfo.text = '${CoolUtil.timeToStr(Conductor.songPosition)} / ${CoolUtil.timeToStr(FlxG.sound.music.length)}'
 		+ '\nStep: ${curStep}'
 		+ '\nBeat: ${curBeat}'
-		+ '\nMeasure: ${curMeasure}';
+		+ '\nMeasure: ${curMeasure}'
+		+ '\nBPM: ${Conductor.bpm}';
 
 		if (FlxG.sound.music.playing) {
 			conductorFollowerSpr.y = curStepFloat * 40;
@@ -1229,16 +1229,10 @@ class Charter extends UIState {
 
 	public function buildChart() {
 		PlayState.SONG.strumLines = [];
-		PlayState.SONG.events = [];
 		for(s in strumLines) {
 			s.strumLine.notes = [];
 			PlayState.SONG.strumLines.push(s.strumLine);
 		}
-		for(e in eventsGroup.members) {
-			for(event in e.events) {
-				PlayState.SONG.events.push(event);
-			}
-		}
 		for(n in notesGroup.members) {
 			var strLineID = Std.int(n.id / 4);
 			if (PlayState.SONG.strumLines[strLineID] != null) {
@@ -1251,6 +1245,33 @@ class Charter extends UIState {
 				});
 			}
 		}
+		buildEvents();
+	}
+
+	public function buildEvents() {
+		PlayState.SONG.events = [];
+		for(e in eventsGroup.members) {
+			for(event in e.events) {
+				event.time = Conductor.getTimeForStep(e.step);
+				PlayState.SONG.events.push(event);
+			}
+		}
+	}
+
+	public function updateBPMEvents(newEvent:CharterEvent) {
+		var hasBPMChange = false;
+		for (event in newEvent.events)
+			if (event.name == "BPM Change") {
+				hasBPMChange = true;
+				break;
+			}
+
+		if (!hasBPMChange) return;
+		buildEvents();
+
+		// Za BPM
+		Conductor.mapBPMChanges(PlayState.SONG);
+		Conductor.changeBPM(PlayState.SONG.meta.bpm, cast PlayState.SONG.meta.beatsPerMesure.getDefault(4), cast PlayState.SONG.meta.stepsPerBeat.getDefault(4));
 	}
 
 	public inline function hitsoundsEnabled(id:Int)

source/funkin/editors/charter/CharterEvent.hx

@@ -77,8 +77,8 @@ class CharterEvent extends UISliceSprite implements ICharterSelectable {
 	}
 
 	public function handleDrag(change:FlxPoint) {
-		step += change.x;
-		y = (step * 40) - 17;
+		y = ((step += change.x) * 40) - 17;
+		Charter.instance.updateBPMEvents(this);
 	}
 
 	public function refreshEventIcons() {

source/funkin/editors/charter/CharterEventAdd.hx

@@ -19,14 +19,13 @@ class CharterEventAdd extends UISliceSprite {
 	public override function onHovered() {
 		super.onHovered();
 		if (FlxG.mouse.justReleased) {
-			var state = cast(FlxG.state, Charter);
 			if (curCharterEvent != null) {
-				FlxG.state.openSubState(new CharterEventScreen(curCharterEvent));
+				Charter.instance.openSubState(new CharterEventScreen(curCharterEvent));
 			} else {
 				var event:CharterEvent = new CharterEvent(step, []);
-				state.eventsGroup.add(event);
+				Charter.instance.eventsGroup.add(event);
 
-				FlxG.state.openSubState(new CharterEventScreen(event));
+				Charter.instance.openSubState(new CharterEventScreen(event));
 			}
 		}
 	}

source/funkin/editors/charter/CharterEventScreen.hx

@@ -69,11 +69,10 @@ class CharterEventScreen extends UISubstateWindow {
 			saveCurTab();
 			chartEvent.refreshEventIcons();
 
-			if (chartEvent.events.length <= 0) {
-				var state = cast(FlxG.state, Charter);
-				state.eventsGroup.remove(chartEvent, true);
-			}
+			if (chartEvent.events.length <= 0)
+				Charter.instance.eventsGroup.remove(chartEvent, true);
 			close();
+			Charter.instance.updateBPMEvents(chartEvent);
 		});
 		saveButton.x -= saveButton.bWidth;
 		saveButton.y -= saveButton.bHeight;