Have an app, running for the last year but last week started getting auth issues on production. Debugging it showed random 403 reported. We published again to a deployment slot, checked everything worked and then did a swap. No success.
What works (on production)
- Chrome/Safari/Edge on desktop
What fails (on production)
- Firefox and Chrome/Android
Everything works on deployment slot and the slot is cloned from production. So apart from remapping the IP address, does anyone know what else swap slots does that might cause this?
PS. It's an MVC.net with a forms authentication cookie.