Ion-datetime working in Vue WebApp but not in iOS app

I have created a WebApp using Vue with a form containing ion-datetime.

  • The picker appears on click → ok
  • Cancel and Take over buttons work → ok
  • Day, month and year can be changed → ok

When I create an iOS app from the same WebApp and open it in the Simulator or on a device:

  • The picker appears on click → ok
  • Cancel and Take over buttons work → ok
  • Day, month and year CANNOT be changed → NOT OK

iOS 14.5
XCode 12.5 beta 3
macOS Big Sur 11.2.3

Any ideas? Thank you!