Peculiar PWA Bug on Safari IOS 13.1.2

Question

I don't know if this is specific to the newest update of IOS 13, but I'm having some really strange PWA behavior. When I initially add it to my homescreen, links on the page open in safari rather than inline on the PWA (none of the links are set to __blank by the way), but when I sign in with oAuth on safari and then add it to my homescreen, it functions like it should and it works normally with links. (Currently using Passport with Node and Express for authentication) I don't know if there's some security infrastructure or something to do with packets, but it's really strange and I'd like to resolve this as soon as I can before my userbase gets frustrated.

I've tried looking through my manifest but everything is up to spec as far as PWA standards go. I have the display set to standalone, I have all my tags setup correctly, Lighthouse audit also says it should work. I've looked through the passport docs, traced my authentication code, but nothing seems to work.

Answer 1

It looks like Apple changed the home screen/standalone web app behavior in iOS 13, but I cannot find any official documentation on this. Now it seems that if you did not have a manifest.json setup before the web app was added to the home screen, it only treats the initial page as being in scope for the standalone view. Hence any other link/redirect opens in another window or the in-app browser.

We have a web app installed on our user's home screens that was written years ago and functioned just fine up until iOS 13 without a manifest.json file. I had to rewrite the WebSQL code in our app to use IndexedDB instead since they completely dropped WebSQL from home screen web apps in iOS 13, even with WebSQL re-enabled in the Safari advanced setting. When I started testing on an iPhone, any link or redirect, even using window.location.assign or any number of other methods would always open the next page in an in-app browser with a minimal UI. This also messed with the page geometry as what was a full height page with no scrolling, was now scrollable with our 'Next' button elements pushed off the bottom of the screen. Since we have some scrollable panels in the middle of some pages it wasn't obvious how to get to the end of the page (you have to scroll a fixed element to scroll the whole page) so that was not going to work for our users.

Long story short, adding a bare minimum manifest.json file to the web app (doesn't even need the scope setting) and deleting and re-adding the web app to the home screen then makes it behave as before with all pages showing in the standalone view. Adding a manifest.json to an already installed home screen app does not affect the behavior.