I have an app that uses auth0 for sign-up/sign-in via Google, Facebook, and email. I typically use email.
My default browser on my Android device has been Firefox Nightly for well over a year, and signing up or signing in with my email address has never been an issue. Today I tried to sign in, but when I press the “Continue with Email” button I get sent to a white screen that says “Found. Redirecting to my.android.package://auth.mydomain.com/blahblah/callback?code=veryLongCode” and it never redirects me. I can’t sign in or sign up via email.
I switched my phone’s default browser to stable Firefox and everything works as expected.
I know that Firefox Nightly is considered pre-production software, but I’m concerned that there might be some new privacy change rolling out to production versions of Firefox in the near future that will break this flow for a lot more people. I found that there was a similar case a few years back with a cookie change related to SameSite, and I see that the change was applied in Firefox Nightly first, and then regular Firefox, so it’s a possibility.
It could just be a bug in Firefox Nightly, but I wanted to start a topic just to see if this is a known issue, or something that others are experiencing.