diff --git a/build/php b/build/php
index 56cec1174..ae946949c 160000
--- a/build/php
+++ b/build/php
@@ -1 +1 @@
-Subproject commit 56cec11745bbd87719a303a0a1de41ee1d1d69c2
+Subproject commit ae946949c528acf8c3f05dfceadc1d66b42d1f2f
diff --git a/changelogs/5.23.md b/changelogs/5.23.md
index 6e72e9403..3a287608f 100644
--- a/changelogs/5.23.md
+++ b/changelogs/5.23.md
@@ -127,3 +127,13 @@ Released 9th December 2024.
 
 ## Internals
 - Removed legacy `build/make-release.php` script. This script is no longer used, as all releases should now follow the PR workflow.
+
+# 5.23.3
+Released 22nd January 2025.
+
+## Fixes
+- Fixed crashes with PHP internal stack frames being flagged as plugin crashes.
+- Fixed note block instrument sounds in 1.21.50.
+
+## Internals
+- Updated GitHub issue templates to use issue forms.
diff --git a/src/VersionInfo.php b/src/VersionInfo.php
index 48ce7dc9e..10a316835 100644
--- a/src/VersionInfo.php
+++ b/src/VersionInfo.php
@@ -31,7 +31,7 @@ use function str_repeat;
 
 final class VersionInfo{
 	public const NAME = "PocketMine-MP";
-	public const BASE_VERSION = "5.23.3";
+	public const BASE_VERSION = "5.23.4";
 	public const IS_DEVELOPMENT_BUILD = true;
 	public const BUILD_CHANNEL = "stable";
 
diff --git a/src/data/bedrock/NoteInstrumentIdMap.php b/src/data/bedrock/NoteInstrumentIdMap.php
index c847ecd98..7f0c0f310 100644
--- a/src/data/bedrock/NoteInstrumentIdMap.php
+++ b/src/data/bedrock/NoteInstrumentIdMap.php
@@ -39,10 +39,10 @@ final class NoteInstrumentIdMap{
 				NoteInstrument::SNARE => 2,
 				NoteInstrument::CLICKS_AND_STICKS => 3,
 				NoteInstrument::DOUBLE_BASS => 4,
-				NoteInstrument::BELL => 5,
-				NoteInstrument::FLUTE => 6,
-				NoteInstrument::CHIME => 7,
-				NoteInstrument::GUITAR => 8,
+				NoteInstrument::FLUTE => 5,
+				NoteInstrument::BELL => 6,
+				NoteInstrument::GUITAR => 7,
+				NoteInstrument::CHIME => 8,
 				NoteInstrument::XYLOPHONE => 9,
 				NoteInstrument::IRON_XYLOPHONE => 10,
 				NoteInstrument::COW_BELL => 11,
diff --git a/src/network/mcpe/NetworkSession.php b/src/network/mcpe/NetworkSession.php
index 511d0dece..fdb63c467 100644
--- a/src/network/mcpe/NetworkSession.php
+++ b/src/network/mcpe/NetworkSession.php
@@ -1058,8 +1058,7 @@ class NetworkSession{
 		];
 
 		$layers = [
-			//TODO: dynamic flying speed! FINALLY!!!!!!!!!!!!!!!!!
-			new AbilitiesLayer(AbilitiesLayer::LAYER_BASE, $boolAbilities, 0.05, 0.1),
+			new AbilitiesLayer(AbilitiesLayer::LAYER_BASE, $boolAbilities, $for->getFlightSpeedMultiplier(), 0.1),
 		];
 		if(!$for->hasBlockCollision()){
 			//TODO: HACK! In 1.19.80, the client starts falling in our faux spectator mode when it clips into a
diff --git a/src/player/Player.php b/src/player/Player.php
index 66ba6f376..1c67b7182 100644
--- a/src/player/Player.php
+++ b/src/player/Player.php
@@ -184,6 +184,8 @@ class Player extends Human implements CommandSender, ChunkListener, IPlayer{
 	private const MAX_REACH_DISTANCE_SURVIVAL = 7;
 	private const MAX_REACH_DISTANCE_ENTITY_INTERACTION = 8;
 
+	public const DEFAULT_FLIGHT_SPEED_MULTIPLIER = 0.05;
+
 	public const TAG_FIRST_PLAYED = "firstPlayed"; //TAG_Long
 	public const TAG_LAST_PLAYED = "lastPlayed"; //TAG_Long
 	private const TAG_GAME_MODE = "playerGameType"; //TAG_Int
@@ -285,6 +287,8 @@ class Player extends Human implements CommandSender, ChunkListener, IPlayer{
 	protected bool $blockCollision = true;
 	protected bool $flying = false;
 
+	protected float $flightSpeedMultiplier = self::DEFAULT_FLIGHT_SPEED_MULTIPLIER;
+
 	/** @phpstan-var positive-int|null  */
 	protected ?int $lineHeight = null;
 	protected string $locale = "en_US";
@@ -518,6 +522,41 @@ class Player extends Human implements CommandSender, ChunkListener, IPlayer{
 		return $this->flying;
 	}
 
+	/**
+	 * Sets the player's flight speed multiplier.
+	 *
+	 * Normal flying speed in blocks-per-tick is (multiplier * 10) blocks per tick.
+	 * When sprint-flying, this is doubled to 20.
+	 *
+	 * If set to zero, the player will not be able to move in the xz plane when flying.
+	 * Negative values will invert the controls.
+	 *
+	 * Note: Movement speed attribute does not influence flight speed.
+	 *
+	 * @see Player::DEFAULT_FLIGHT_SPEED_MULTIPLIER
+	 */
+	public function setFlightSpeedMultiplier(float $flightSpeedMultiplier) : void{
+		if($this->flightSpeedMultiplier !== $flightSpeedMultiplier){
+			$this->flightSpeedMultiplier = $flightSpeedMultiplier;
+			$this->getNetworkSession()->syncAbilities($this);
+		}
+	}
+
+	/**
+	 * Returns the player's flight speed multiplier.
+	 *
+	 * Normal flying speed in blocks-per-tick is (multiplier * 10) blocks per tick.
+	 * When sprint-flying, this is doubled to 20.
+	 *
+	 * If set to zero, the player will not be able to move in the xz plane when flying.
+	 * Negative values will invert the controls.
+	 *
+	 * @see Player::DEFAULT_FLIGHT_SPEED_MULTIPLIER
+	 */
+	public function getFlightSpeedMultiplier() : float{
+		return $this->flightSpeedMultiplier;
+	}
+
 	public function setAutoJump(bool $value) : void{
 		if($this->autoJump !== $value){
 			$this->autoJump = $value;