Are you submitting a bug report or a feature request?

Bug? I guess.

What is the current behavior?

Form onChange is called only on attachToForm but it doesn't called when you remove an input.

working example: https://codesandbox.io/s/formsy-vnfvm?file=/src/index.js

Please the following update

From the migration guide, this wroked for me to fix the issue :

If you previously used overflow: Overflow.visible, you shall replace it with clipBehavior: Clip.none.

For ListWheelViewport widget, if you previously specified clipToSize, replace it with the corresponding clipBehavior: Clip.none for clipToSize = f

For a long time I thought this was impossible to do without writing toString/fromString functions for your custom types, but I just realized that you can make it work by instead using the list index of the options as the "value", and then in the onChange decoder use that index to retrieve the item from the passed in options list.

Here's a demo: https://ellie-app.com/7253Q8THR2xa1