How can I experiment with multi vehicle simulation?

I used the manual on the official site for multi simulation, but my drone is not working, the topics of the drone are also split and working fine, but my code is not working the drone is not working in multi sim, but in normal single simulation it is working perfectly.

I ran the simulation using the following commands

  1. PX4_SYS_AUTOSTART=4001 PX4_SIM_MODEL=gz_x500 ./build/px4_sitl_default/bin/px4 -i 1

  2. PX4_SYS_AUTOSTART=4001 PX4_GZ_MODEL_POSE=“0,1” PX4_SIM_MODEL=gz_r1_rover ./build/px4_sitl_default/bin/px4 -i 2

Give me advice
Thank you!!

You can see the topics, so perhaps the problem is your code - are you subscribing/publishing to the correct instances?

Please confirm also you are indeed working on PX4 v1.14.