This isn't a Minecraft bug, but a bug with the feedback website. It's no longer possible to log into it. When you click the Login link at the top right, it generates a URL and then just stops. It's not hung, it just stops working at a blank screen. This was in Chrome, where I always logged in previously.
So, I tried Edge, and there Microsoft tried to force me to use a different account (one of my outlook.com accounts), which wouldn't work so I quit trying.
Since there's no way to report the problem on the feedback site, I'm reporting it here in the hopes that someone can contact them and get the problem fixed.
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duplicates
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Thank you for your report!
We're tracking this issue in WEB-4582, so this ticket is being resolved and linked as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
If you haven't already, you might like to make use of the search feature to see if the issue has already been mentioned.
Quick Links:
📓 Bug Tracker Guidelines – 💬 Community Support – 📧 Mojang Support
📓 Project Summary – ✍️ Feedback and Suggestions – 📖 Game Wiki

Thank you!
It might be temporary. There is a project called Mojang Web Services (WEB) in the drop down menu. Site issues probably belong there.