Edge Smartscreen Falsely Reporting our Paywall/Protected Content Log In box as Phishing

Help urgently needed.

Five days ago Edge's Smartscreen started showing a red warning screen when our customers go to the Log In box on our homepage to log into their subscription to our password protected content for which they are paid to have access. The homepage shows as clean it's only the actual Log In box page where the warning shows as a 'phishing' attempt with a red screen.

I submitted the "this is a safe site" report four days ago as the owner. Our customers are also submitting "this is a safe site" reports each day. I have also been contacting the Smartscreen team via the original case number/email each 24 hours but there is no response and no change to the warning screen.

I have checked our site against the Microsoft toolbox and the site gets green checks against everything. Google and all other browsers show our site as clean, the warning is only in Edge.

It is only the actual Log In box that requires the customer to put in their 'username' and software assigned 'password' that is showing the warning screen as a phishing attempt.

We use no trackers or cookies, adhere to all of Microsoft's recommended practices. It's like our 'safe' reports back to them are falling into a black hole.

The code used to produce the Log In box has been working perfectly for 7 years so I don't think it can be the code.

Does anyone have any ideas please as this is causing us and our customers a great deal of anxiety and worse we're worried about how it will affect our reputation and future business.

We've been in business for 30 years in defence journalism, are highly regarded for our accuracy and fair reporting, pay for very expensive secure hosting and our site is clean, scanned constantly for intrusions.

I'm both frustrated and at wit's end as to how to fix this.

Any thoughts or suggestions would be greatly appreciated and if I've posted this in the wrong area please let me know the correct one to put it in.