TextField looses focus on .withStatusLabel on FormLayout

Hi,

i've had an issue with the input-focus while using the binders .withStatusLabel on a textfield. The following snippet is reproducing the problem. If I focus the (empty) textfield and enter some text the status-label is hidden and the input-field looses focus. If i refocus the input and clear all text the status-label is made visible and the input looses focus again.
If i use a HorizontalLayout instead of a Formlayout the problem doesn't appear, the focus is kept regardless of the status-label.

TextField fieldA = new TextField("Field A");
Label errorA = new Label();
FormLayout form = new FormLayout(fieldA, errorA);
binder.forField(fieldA)
          .asRequired("required")
          .withStatusLabel(errorA)
          .bind(ImageViewerDemoUI::getA, ImageViewerDemoUI::setA);

Vaadin-Version 8.1.6
Demo-Projekt: vaadin-tester.zip

Start by reproducing the provided TextField, FormLayout, and Binder.withStatusLabel example on Vaadin 8.1.6, then compare it with the HorizontalLayout variant. The fix is complete when showing or hiding the status label no longer causes the focused input to lose focus.