execsnoop missing data for popen

[MICHALRAT]

I conducted the following test:

int main() {
    const char* command = "ls -l";    
    FILE* pipe = popen(command, "r");
    if (pipe == NULL) {
        
        return 1;
    }
    pclose(pipe);
    return 0;
}

popen internally calls execl("/bin/sh", "sh", "-c", command, (char *)0);
which calls __execve (path, (char *const *) argv, __environ);, for some reason the internal 'sh -c' process is missing its data as can be seen from the trace_pipe log below, it appears empty:

<...>-77063 [004] .... 693824.892595: sched_process_fork: comm=bash pid=77063 child_comm=bash child_pid=94755
<...>-94755 [005] d... 693824.892959: execsnoop_sys_execve: (SyS_execve+0x0/0x40) arg1="./popen_test" arg2=(fault) arg3=(fault) arg4=(fault) arg5="" arg6=(fault) arg7=(fault) arg8=(fault) arg9=(fault)
<...>-94755 [006] .... 693824.893857: sched_process_fork: comm=popen_test pid=94755 child_comm=popen_test child_pid=94756
 <...>-94756 [007] d... 693824.893981: execsnoop_sys_execve: (SyS_execve+0x0/0x40) arg1=(fault) arg2=(fault) arg3=(fault) arg4=(fault) arg5=(fault) arg6=(fault) arg7=(fault) arg8=(fault) arg9=(fault)
<...>-94756 [000] d... 693824.896085: execsnoop_sys_execve: (SyS_execve+0x0/0x40) arg1="ls" arg2="-l" arg3=(fault) arg4=(fault) arg5=(fault) arg6=(fault) arg7=(fault) arg8=(fault) arg9=(fault)

This happens only form within popen, when I tested execl("/bin/sh", "sh", "-c", command, (char *)0); explicitly the data was traced correctly.
What could be the cause for this issue?