iFrame error

Have something happened to the iFrame security settings?

We are suddenly not able to access any iFrame urls from dev, but it works fine in test and prod, even after deploy to test.

I have also tested to access the appfarm site in iFramTester.com, and same result, I access it in test but not in dev. iFrameTester url is added as Ancestor in both test and dev.


Now it is suddenly working again. Out for some hours only. Weird.