When components were initially rendered more than once, in consecutive
microtask ticks, the order of two actions was reversed: the assignation
of the vnode to the __owl__.vnode property, and the assignation of
__owl__.vnode to the final rendered vdom of the component.
As a result, the widget was rendered as null (so, not present).
The reason for this issue was that the renderPromise key was reassigned
at some point.
Géry Debongnie