Login Button Doesn't Work in Facebook Messenger in-app browser on Mobile

So my login is based very closely on the Angular SPA getting started flow. When I share a link to my app with my friends via Facebook messenger on a phone it opens the page, and they are logged out. But when they click the login button, which is bound to (click)="auth.loginWithPopup()" nothing happens. It works like it’s supposed to if you visit the page in Chrome instead. It seems like it works in Facebook messenger if I use auth.loginWithRedirect()… does this make sense?

I’m not clear about how to diagnose it further. I can’t see the Facebook browser on the Phone using chrome://inspect on my laptop for example. I’m just totally blind as to what is happening when I click my login button in this context. Any help or suggestions would be greatly appreciated.

Things seem to work worse on iPhones when you use loginWithRedirect() though… I’m so confused :confused:… I feel like I must be doing it wrong - can anyone help me figure out how to make login work universally?