External preview for 100% height vertical layout does not fit iPhone safari

Steps to reproduce

    static get template() {
        return html`
<style include="shared-styles">
                :host {
                    display: block;
                    height: 100%;
                }
            </style>
<vaadin-vertical-layout style="width: 300px; height: 100%; align-items: stretch; margin: auto; justify-content: flex-start; " theme="spacing padding">
 <vaadin-vertical-layout theme="spacing" style="align-items: stretch;">
  <vaadin-button>
   <iron-icon icon="vaadin:facebook" slot="prefix"></iron-icon>Continue with Facebook
  </vaadin-button>
  <vaadin-button>
   <iron-icon icon="vaadin:twitter" slot="prefix"></iron-icon>Continue with Twitter
  </vaadin-button>
 </vaadin-vertical-layout>
 <vaadin-vertical-layout theme="spacing" style="align-items: stretch;">
  <span style="align-self: center;">OR</span>
  <vaadin-text-field label="" placeholder="Username"></vaadin-text-field>
  <vaadin-password-field label="" placeholder="password" value="secret1"></vaadin-password-field>
 </vaadin-vertical-layout>
 <vaadin-vertical-layout theme="spacing" style="align-items: stretch; flex-grow: 1;">
  <vaadin-checkbox style="align-self: center;">
   Keep me logged in
  </vaadin-checkbox>
  <vaadin-button theme="primary">
   Login
  </vaadin-button>
 </vaadin-vertical-layout>
 <vaadin-button theme="tertiary">
  Forgot password?
 </vaadin-button>
 <vaadin-button theme="tertiary">
   New user? 
 </vaadin-button>
</vaadin-vertical-layout>
`;
    }

Actual behavior

The design does not fit iPhoneX screen in external preview. Works in design canvas resizing and works in external preview on desktop Chrome with the inspector set to show page as iPhoneX. But not on the actual device. The vertical layout looks very close to just as much higher than the iOS Safari UI takes from the screen height.

IDE, Designer and OS version

OS: Windows 10 10.0 amd64 Browser: Mozilla/5.0 (Windows NT 6.2; Win64; x64; Trident/7.0; rv:11.0) like Gecko Java: 1.8.0_181 Eclipse: org.eclipse.epp.package.jee.product 4.12.0.20190614-1200 Designer: 4.3.8

IOS 13.2.3

Hello there!

It looks like this issue hasn't progressed lately. There are so many issues that we just can't deal them all within a reasonable timeframe.

There are a few things you could help to get things rolling on this issue (this is an automated message, so expect that some of these are already in use):

Check if the issue is still valid for the latest version. There are many duplicates in our issue tracker, so it is possible that the issue is already tackled.
Provide more details how to reproduce the issue.
Explain why it is important to get this issue fixed and politely draw others attention to it e.g. via the forum or social media.
Add a reduced test case about the issue, so it is easier for somebody to start working on a solution.
If the issue is clearly a bug, use the Warranty in your Vaadin subscription to raise its priority.

Thanks again for your contributions! Even though we haven't been able to get this issue fixed, we hope you to report your findings and enhancement ideas in the future too!

vaadin / designer