PWA standalone issue in ios 11.3

What is the question? I don't see a question here. Are you asking why it opens in the browser not in standalone mode? Did you include the login page with the standalone (mobile web app capable) code? It likely depends on how you included it and/or how you are opening the login page as well as where the login page exists (domain wise)

Is the login page on the same domain as the PWA app entry code?

Given the need to authenticate outside the scope of the PWA and the change in behavior for security purposes, what is the recommended means in which to get credentials back inside the scope of a PWA, or is there a way to mimic the more preferable behavior that is seen in Android Chrome (see below)?

For example, our company builds a PWA and has our users install to home screen. Once installed, they can enter their site and if they use SAML authentication, it will redirect to their IDP to get their credentials, which (now) falls out of the scope of the PWA. Before, the scope was unbounded and this was perfectly fine. Now, IOS opens a new Safari window, does the authentication there, and they never land back in the context of the PWA.

It appears a number of people are having similar issues, most likely related to this change:

https://github.com/w3c/manifest/issues/550

Here is another example of people in the same boat:

https://github.com/nolanlawson/pinafore/issues/45

Android Chrome continues to work because of their implementation, which simply warns you are outside the scope of the PWA but continues within the sandbox. See here:

https://github.com/w3c/manifest/issues/646

I try all the solutions but nothing can help me

When I read on this website: https://tapita.io/

They mentioned that the error belongs to the code of the Pwa so the owner should code it again