Starting new process from .net6 app with stderror redirected crashes the app with "StandardError has not been redirected."

Question

I am trying to run a process and read its stdoutput and stderror from a .net6 console app. The code:

public Process Run(string command, string args)
{
    var psi = new ProcessStartInfo
        {
            FileName = command,
            Arguments = args,
            UseShellExecute = false,
            RedirectStandardOutput = true,
            RedirectStandardError = true,
            CreateNoWindow = true
        };

    var p = new System.Diagnostics.Process { StartInfo = psi, EnableRaisingEvents = true };

    p.ErrorDataReceived += (sender, e) => ...
    p.OutputDataReceived += (sender, e) => ...
    p.Exited += async (sender, e) =>
        {
            // this allows to wait until we read both StandardOutput and StandardError asynchronously; without it we get more stdOut data after Exited event...
            // https://stackoverflow.com/a/17600012/5033397
            await p.WaitForExitAsync();
            p.Dispose();
        };

    p.Start();
    p.BeginOutputReadLine();
    p.BeginErrorReadLine();

    return p;
}

It works 99% of the time, but I am getting this error intermittently (might happen once every few hours or so while the app is running on a server):

System.InvalidOperationException: StandardError has not been redirected.
at System.Diagnostics.Process.BeginErrorReadLine()
at ProcessRunner.Run(String command, String args) in /app/ProcessRunner.cs:line 88

This happens both Windows and Linux. Processes being executed with code above:

• iostat
• typeperf
• ffprobe
• ffmpeg

What could be wrong with this setup?