ColorPickerPopup opens in Background?

Hello Community,

i am fairly new to Vaadin and i have run into a Bug i cannot fix.

Component component = new ColorPicker(caption, hex2Rgb(settings.get(constant)));
GridLayout gridLayout = new GridLayout();
gridLayout.addComponent(component);
valuePanel.setContentLayout(gridLayout);

When i click on the ColorPicker the popup opens, but it is grayed out and i cannot interact with it. The only way to close it is by clicking the ColorPicker Button again. When clicking the third time the popup opens in front and it’s working.

Does anybody have a clue why and how to fix it?

Thank you a lot!