diff --git a/client.go b/client.go
index d80974c..9f66554 100644
--- a/client.go
+++ b/client.go
@@ -1021,6 +1021,10 @@ func (c *Client) stop() error {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
+	if c.peerConnection.pc.ConnectionState() == webrtc.PeerConnectionStateClosed {
+		return nil
+	}
+
 	err := c.peerConnection.Close()
 	if err != nil {
 		return err
diff --git a/clienttracksimulcast.go b/clienttracksimulcast.go
index 54ff9c5..2b5b4b7 100644
--- a/clienttracksimulcast.go
+++ b/clienttracksimulcast.go
@@ -113,6 +113,10 @@ func (t *simulcastClientTrack) push(p *rtp.Packet, quality QualityLevel) {
 
 	targetQuality := t.getQuality()
 
+	if targetQuality == QualityNone {
+		return
+	}
+
 	if !t.client.bitrateController.exists(t.ID()) {
 		// do nothing if the bitrate claim is not exist
 		return
@@ -285,6 +289,10 @@ func (t *simulcastClientTrack) getQuality() QualityLevel {
 
 	claim := t.client.bitrateController.GetClaim(t.ID())
 
+	if claim == nil {
+		return QualityNone
+	}
+
 	quality := min(claim.quality, t.MaxQuality(), Uint32ToQualityLevel(t.client.quality.Load()))
 
 	if quality != QualityNone && !track.isTrackActive(quality) {
diff --git a/clienttracksvc.go b/clienttracksvc.go
index d8d881f..ea16ad9 100644
--- a/clienttracksvc.go
+++ b/clienttracksvc.go
@@ -49,17 +49,16 @@ func DefaultQualityPresets() QualityPresets {
 
 type scaleableClientTrack struct {
 	*clientTrack
-	lastQuality     QualityLevel
-	maxQuality      QualityLevel
-	tid             uint8
-	sid             uint8
-	lastTimestamp   uint32
-	lastSequence    uint16
-	baseSequence    uint16
-	qualityPresets  QualityPresets
-	hasInterPicture bool
-	init            bool
-	packetCaches    *packetCaches
+	lastQuality    QualityLevel
+	maxQuality     QualityLevel
+	tid            uint8
+	sid            uint8
+	lastTimestamp  uint32
+	lastSequence   uint16
+	baseSequence   uint16
+	qualityPresets QualityPresets
+	init           bool
+	packetCaches   *packetCaches
 }
 
 func newScaleableClientTrack(
@@ -103,14 +102,7 @@ func (t *scaleableClientTrack) isKeyframe(vp9 *codecs.VP9Packet) bool {
 func (t *scaleableClientTrack) push(p *rtp.Packet, _ QualityLevel) {
 	var qualityPreset IQualityPreset
 
-	t.mu.RLock()
-	isLatePacket := IsRTPPacketLate(p.SequenceNumber, t.lastSequence)
-	t.mu.RUnlock()
-
-	if !t.init {
-		t.init = true
-		t.baseSequence = p.SequenceNumber
-	}
+	var isLatePacket bool
 
 	vp9Packet := &codecs.VP9Packet{}
 	if _, err := vp9Packet.Unmarshal(p.Payload); err != nil {
@@ -137,18 +129,15 @@ func (t *scaleableClientTrack) push(p *rtp.Packet, _ QualityLevel) {
 	targetSID := qualityPreset.GetSID()
 	targetTID := qualityPreset.GetTID()
 
-	if !t.hasInterPicture {
-		if !vp9Packet.P {
-			t.baseSequence++
-			t.RequestPLI()
-			glog.Info("scalabletrack: packet ", p.SequenceNumber, " client ", t.client.ID(), " is dropped because of no intra frame")
-			return
-
-		}
-
-		t.hasInterPicture = true
+	if !t.init {
+		t.init = true
+		t.baseSequence = p.SequenceNumber
 		t.sid = targetSID
 		t.tid = targetTID
+	} else {
+		t.mu.RLock()
+		isLatePacket = IsRTPPacketLate(p.SequenceNumber, t.lastSequence)
+		t.mu.RUnlock()
 	}
 
 	currentBaseSequence := t.baseSequence
diff --git a/manager.go b/manager.go
index b2db5ae..9c44e4d 100644
--- a/manager.go
+++ b/manager.go
@@ -5,6 +5,7 @@ import (
 	"errors"
 	"sync"
 
+	"github.com/golang/glog"
 	"github.com/pion/webrtc/v3"
 )
 
@@ -107,31 +108,25 @@ func (m *Manager) NewRoom(id, name, roomType string, opts RoomOptions) (*Room, e
 		}
 	})
 
-	var emptyRoomTimeout context.Context
+	idle := true
 
 	var emptyRoomCancel context.CancelFunc
 
+	_, emptyRoomCancel = startRoomTimeout(m, room)
+
 	room.OnClientLeft(func(client *Client) {
 		if room.SFU().clients.Length() == 0 {
-			emptyRoomTimeout, emptyRoomCancel = context.WithTimeout(m.context, room.options.EmptyRoomTimeout)
-			go func() {
-				<-emptyRoomTimeout.Done()
-				if emptyRoomTimeout.Err() == context.DeadlineExceeded {
-					m.mutex.Lock()
-					defer m.mutex.Unlock()
-					room.Close()
-					delete(m.rooms, room.id)
-					emptyRoomCancel = nil
-					emptyRoomTimeout = nil
-				}
-			}()
+			idle = true
+			_, emptyRoomCancel = startRoomTimeout(m, room)
 		}
 	})
 
 	room.OnClientJoined(func(client *Client) {
-		if emptyRoomTimeout != nil && emptyRoomCancel != nil {
+		if idle {
 			emptyRoomCancel()
 		}
+
+		idle = false
 	})
 
 	m.rooms[room.id] = room
@@ -218,3 +213,24 @@ func (m *Manager) Close() {
 func (m *Manager) Context() context.Context {
 	return m.context
 }
+
+func startRoomTimeout(m *Manager, room *Room) (context.Context, context.CancelFunc) {
+	var cancel context.CancelFunc
+
+	var ctx context.Context
+
+	ctx, cancel = context.WithTimeout(m.context, room.options.EmptyRoomTimeout)
+
+	go func() {
+		<-ctx.Done()
+		if ctx.Err() == context.DeadlineExceeded {
+			m.mutex.Lock()
+			defer m.mutex.Unlock()
+			room.Close()
+			delete(m.rooms, room.id)
+			glog.Info("room ", room.id, " is closed because it's empty and idle for ", room.options.EmptyRoomTimeout)
+		}
+	}()
+
+	return ctx, cancel
+}