Here's what you do:
When you get the warning, click More information
Select Disregard and continue (not recommended).
After site loads, note the URL address bar has the unsafe site warning. Click Unsafe website
In the popup, click Report that this site does not contain threats
This will take you to a Feedback screen you can fill in to say (and select the radio button for this) I think this is a safe site.
Then fill in the characters shown below and click Submit.
If several of us do this, it will remove the unsafe report.
Is there a phishing threat on the site? That’s the reason the there was an alert.