Error with icon editing in new designer mode

Product: PowerShell Universal
Version: 4.0.1

I am thinking of reverting our lab back to 3.x as I cannot do any dashboard aka app work without running into an issue. This time it is adding Icons.

When I add an Icon to say a button, I edit the button, edit the Icon and type the icon as ‘plus’.
Next time I edit the component and try to edit the Icon I get the below error message.

I really like the new UI and the other improvements, but thinking I will wait before moving forward with using Designer for now.