Props inside nested `v-async-target` are not reactive

[aabounegm]

I have a component whose template loads another component asynchronously, and then inside its default slot I load another component asynchronously. The props passed into the nested async component are not reacting to changes in the value, even though the change can be seen in the template itself. To clarify, given the following example:

< b-button @onClick = openBottomSlide
    Open bottom slide

< . v-async-target
    += self.loadModules('components/dummies/b-dummy')
        < b-dummy
            < . v-async-target
                += self.loadModules('components/base/b-bottom-slide')
                    < b-bottom-slide :heightMode = heightMode
                        < p
                            Height mode: {{ heightMode }}

                        < b-button @onClick = triggerHeightMode
                            Trigger height mode

triggering height mode should switch it from 'content' to 'full', and it does change in the p element, but the b-bottom-slide prop does not get the updated value (as seen in the V4Fire DevTools) and hence the modifier is also not changed.

A reproducible example can be found in the branch examples/1472