URL: https://my.acque.net/acque/it/login

Browser / Version: Firefox 70.0
Operating System: Linux, Windows, Mac
Tested Another Browser: Yes

Problem type: Something else
Description: SSL_ERROR_UNKNOWN_CA_ALERT
Steps to Reproduce:
The website use a DigiCert certificate. How to reproduce:

1. Open the website https://my.acque.net/acque/it/login
2. Click the button "ACCEDI" or "Password dimenticata?" in the middle white form on the bottom of that page.
3. The certificate error occurs

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