How to rectify?

We had a warning about our Privacy Policy not being accessible and that our app would be disabled if we did not update (we may have had a period of downtime)
We now confirmed that the privacy policy back up but the app has been disabled. when i try to resolve the issue and i enter the url we get an error saying Something went wrong. Refresh the page, and then make your update and submit the form again. when adding privacy policy"
We have even changed the url but still have the issue

I've doing such things since more than 2 decades. But the experience with the meta app review team is the worst I ever had.
My app is rejected since weeks. They simply don't give me helpful informations. When I'm (and others from the team) testing the app with the test user provided, it simply works. But the review team constantly rejecting with the reason the login throws an error.
We are playing ping-pong since weeks - at least 20 submits/rejects.
What can I do? Is there a possibility to get any proper feedback, like a screenshot or screencast to see what they do.