It's a little weird.
I used the command you recommend, my destination was an IP camera.
When we have the SXL enabled on the CP, the CCTV server cannot see the video from the camera, but the command
fw ctl zdebug + drop | grep <IP CAMERA> ... at that time it shows me nothing.
It is as if for the FW everything is working fine.
Then, when we disable the SXL, immediately the CCTV server retrieves the video from the camera.
Only the “fw ctl zdebug + drop” is the command that helps to detect if it is the SXL that is giving problems?