Java Swing Window

Problem description

The output window is being blocked with Java swing. I am getting the following error:

Diagnosis
If you see a browser error, it's possible that your ISP have security settings blocking the URL. Please contact your ISP and ask them to unblock the URL above. Here are the support links for common ISPs:

Xfinity
Spectrum.net

Expected behavior

The expected output should draw shapes on an output canvas.

Actual behavior

Getting this error:

Diagnosis
If you see a browser error, it's possible that your ISP have security settings blocking the URL. Please contact your ISP and ask them to unblock the URL above. Here are the support links for common ISPs:

Xfinity
Spectrum.net

Steps to reproduce

This seems to work when connecting to my mobile hotspot but not with any other wifi.

Browser

Chrome

OS

Windows

Device if mobile

N/A

Plan

free tier