Firefox add-on's native application runs only once - google-chrome

Question

I have published a native messaging add-on on Mozilla, but the native messaging host (native app) runs only once, if I restart firefox, the native app does not start.
Here is the scenario:
Step 1: I install the native app on Windows 10 using the setup file, the setup also configures the registry key under
HKEY_CURRENT_USER\Software\Mozilla\NativeMessagingHosts
HKEY_LOCAL_MACHINE\Software\Mozilla\NativeMessagingHosts\
Step 2: Start firefox, download and install the public released (signed) add-on from mozilla. The add-on icon shows on Firefox, I click the icon, the add-on popup page shows, click the menu items on the popup, the add-on works as expected, the native app works too, it receives messages from add-on, and sends messages back to the add-on.
All is OK, it seems the native messaging add-on works well. However, after I restart firefox, click the add-on icon, click the menu items on the popup menu, nothing happens. I type about:debugging, in the console window, there is error message "Unchecked lastError value: Error: port is null".
This error only happens while using the signed add-on, using local version un-signed addon, the native messaging host and add-on always run, no such problem.
I want to know, when download and install the addon from Mozilla, except the addon's XPI file, are there other files also downloaded? Maybe these other files run after firefox restarts, and these files or their configuration prevent the native app from running.
Here is the code snippet in background page:
function connectToNativeHost()
{
var nativeHostName = “com.some-company.test”;
port = chrome.runtime.connectNative(nativeHostName);
console.log(port)
port.onMessage.addListener(onNativeMessage);
port.onDisconnect.addListener(onDisconnected);
}
function onDisconnected()
{
console.log(chrome.runtime.lastError);
console.log(‘disconnected from native app.’);
port = null;
}
I test again and again, I find that after firefox restarts, the native app never runs again, firefox does not create a process for the native app.
Thank you for your help!