AuthSession.startAsync - voiceover doesn't focus on datepicker popup button

Hi community!

We are working on an app that has accessibility requirements and needs to be VPAT compliant. Using ADB2C as the identity provider through the AuthSession.startAsync API everything works fine until in iOS using the voiceover (screen reader) we want to access a date picker that renders as a popup button. The issue is that the “Done” button is not accessible with the navigator, instead of focusing on the “Done” button it goes to the form (see following images to clarify the situation). Same approach but from the web browser works fine, so we think that the issues is related with the browser that AuthSession handles to authenticate. Is there a way to handle the focus?

As you can see from the browser that AuthSession opens I cannot reach the Done button. Instead, from the browser, I can hit that!
image

Any idea of what we can do to fix that?
Thanks!