bug: datetime intersection observers get disconnected when changing presentation programmatically

[averyjohnston]

Prerequisites

• I have read the Contributing Guidelines.
• I agree to follow the Code of Conduct.
• I have searched for existing issues that already report this problem, without success.

Ionic Framework Version

• v4.x
• v5.x
• v6.x

Current Behavior

When ion-datetime has its presentation prop changed programmatically, the intersection observers driving month selection seem to be getting disconnected. This causes all sorts of buggy behavior.

Screencast: https://user-images.githubusercontent.com/90629384/138342256-4571c211-d08b-473f-a96a-055e2a4886c8.mp4

Expected Behavior

Month selection should function normally after changing the presentation.

Steps to Reproduce

1. Visit the existing display test for datetime.
2. Change the "Presentation" dropdown to something else.
3. Try to change the month via the arrow buttons.

Code Reproduction URL

http://localhost:3333/src/components/datetime/test/display

Ionic Info

[WARN] You are not in an Ionic project directory. Project context may be missing.

Ionic:

   Ionic CLI : 6.17.1

Utility:

   cordova-res : 0.15.3
   native-run  : 1.4.1

System:

   NodeJS : v16.13.0
   npm    : 8.1.0
   OS     : Windows 10

Additional Information

No response

[arnotixe]

Wonder if this is related to my bug? I have ionic 6.0.9 with a datetime modal on A TAB page 'tab2' ("tabs" starter template) and it seems to "disconnect" from the open-modal trigger when i router.navigate() to another tab. Code is copied straight from the example page https://ionicframework.com/docs/api/datetime

• Switching from tab2 to tab1 back and forth many times does not disconnect the popover trigger.
• Navigating from tab1 to tab2 with router.navigatebyurl() after having switched tabs from 2 to 1 first disconnects
• Refreshing tab1 and router.navigatebyurl(tab2) it is not disconnected.
• Refreshing tab2 after a disconnect "fixes" the disconnect

<ion-button id="open-modal>
<ion-modal trigger="open-modal">
            <ng-template>
              <ion-content> etc```

[averyjohnston]

@arnotixe That sounds like something else; could you open a separate issue?

[averyjohnston]

Resolved via: #24828

[ionitron-bot]

Thanks for the issue! This issue is being locked to prevent comments that are not relevant to the original issue. If this is still an issue with the latest version of Ionic, please create a new issue and ensure the template is fully filled out.