But after logining into my account, it returns "xmlhttp.status: 0"  "Network request failed" immediately when I trying to do the same thing.

I am writing a WebExtension to communicate with a server using XMLHttpRequest. I load this WebExtension temporarily by about:debugging. It works well if I do not login into my Firefox account. It can get data from the server. But after logining into my account, it returns "xmlhttp.status: 0" "Network request failed" immediately when I trying to do the same thing. I removed all other add-ons and WebExtensions, But still I have this problem. I have to refresh firefox to make my extension work again. Any suggestions will be appreciated.