SSL doesn't work in anything other than Safari on MacOS Big Sur

  1. Go to Keychain app.
  2. Select the certificate with the website name you created and double click it:

  1. Select the small trust arrow and select always trust:

  1. Close the certificate window. It will ask you for your admin password to save the changes.
  2. Close the browser, close the Local app, Open browser and empty browser cache.
  3. Open Local app again and Enjoy SSL and HTTPS local website without any errors from chrome etc.