website: add troubleshooting note for VR teleop connection (#513)

Author: abetomo

website/docs/tutorial/data-collection.mdx

@@ -32,6 +32,11 @@ Sideload the APK onto your Quest 3 via Developer Hub.
 4. Verify communication from the PC host:
    `nc -lu 5006`
 
+   :::tip
+   If you don't see any incoming data, another remote control APK on the Quest may be interfering.
+   Try disabling other apps and check again.
+   :::
+
 5. Tape the center-of-eye sensor on the headset to keep it constantly activated (prevents the display from sleeping when worn at the neck).
    Before taping the sensor:
    <BlockImage src="tutorial/data-collection/headset_uncover.png" alt="Headset sensor uncovered" width="90%" />