This is a known "feature" of Twitter. If it assumes the user can be logged in, it will hold the page captive until you sign in. I've had it happen to me, though

This is a known "feature" of Twitter. If it assumes the user can be logged in, it will hold the page captive until you sign in. I've had it happen to me, though I'm not sure of the details. Like whether it's being A/B tested or what specifically it's hitting on to require login