There have been a few reports of this today, so it's more glitchy than normal it seems.
Try this it might work. Click on your feedback score, then up above on the link Feedback Forum. On that page to the right you will see ... Leave Feedback.
Use a desktop browser, not a mobile browser and not an app, see how you get on.
Do remember you have 60 days, in which to leave feedback, too.
