In the "upgrade" case (when an element is registered and there are elements in the _awaitingUpgrade map for that tag name), we were failing to run connectedCallback(). If the stand-in element definition was defined in the global registry first, then we would have no-opted the initial connectedCallback(), and so when manually upgrading the element later, we need to be sure to run its connectedCallback if isConnected === true.
In the "upgrade" case (when an element is registered and there are elements in the
_awaitingUpgrademap for that tag name), we were failing to runconnectedCallback(). If the stand-in element definition was defined in the global registry first, then we would have no-opted the initialconnectedCallback(), and so when manually upgrading the element later, we need to be sure to run itsconnectedCallbackifisConnected === true.Fixes #442