diff --git a/.env b/.env
index 82cc01ccb..0d994bc51 100644
--- a/.env
+++ b/.env
@@ -12,7 +12,7 @@ PROJECT_NAME="airstack"
 # If you've run ./airstack.sh setup, then this will auto-generate from the git commit hash every time a change is made 
 # to a Dockerfile or docker-compose.yaml file. Otherwise this can also be set explicitly to make a release version.
 # auto-generated from git commit hash
-VERSION="0.19.0-alpha.3"
+VERSION="0.19.0-alpha.4"
 # Choose "dev" or "prebuilt". "dev" is for mounted code that must be built live. "prebuilt" is for built ros_ws baked into the image
 DOCKER_IMAGE_BUILD_MODE="dev"  
 # Where to push and pull images from. Can replace with your docker hub username if using docker hub.
diff --git a/robot/ros_ws/src/perception/perception_bringup/launch/perception.launch.xml b/robot/ros_ws/src/perception/perception_bringup/launch/perception.launch.xml
index e433e94d4..a79ff85a1 100644
--- a/robot/ros_ws/src/perception/perception_bringup/launch/perception.launch.xml
+++ b/robot/ros_ws/src/perception/perception_bringup/launch/perception.launch.xml
@@ -50,6 +50,7 @@
                     to="/$(env ROBOT_NAME)/perception/stereo_image_proc/disparity" />
 
                 <param name="speckle_size" value="300" />
+                <param name="approximate_sync" value="true" />
             </node>
             <!-- Point Cloud Generation -->
             <node
@@ -69,6 +70,7 @@
                 <!-- outputs -->
                 <remap from="disparity" to="/$(env ROBOT_NAME)/perception/stereo_image_proc/disparity" />
                 <remap from="points2" to="/$(env ROBOT_NAME)/perception/stereo_image_proc/point_cloud" />
+                <param name="approximate_sync" value="true" />
             </node>
         </group>
 
diff --git a/simulation/isaac-sim/extensions/PegasusSimulator b/simulation/isaac-sim/extensions/PegasusSimulator
index fe8b5a101..8c7a66409 160000
--- a/simulation/isaac-sim/extensions/PegasusSimulator
+++ b/simulation/isaac-sim/extensions/PegasusSimulator
@@ -1 +1 @@
-Subproject commit fe8b5a101857f2cda290b9b677b3a95c4cca6b09
+Subproject commit 8c7a664095396bc9c4f4609531445d4cf6390fe4