Both elements sent their first summer-action from connectedCallback and
kept it in flight forever when the host dropped it (the v0.5.1 widget host
appends the element before it keeps a reference). A shared ActionQueue no
longer trusts that an emitted action was taken: one the host did not mark
busy synchronously is retried once on the next task, a second drop shows
an error, and a disconnect forgets the request in flight. The first
request is sent on a microtask. Element tests drive a fake host that
mirrors WidgetField's contract, including the append-first ordering, and
the robots.txt tester gets its own tests.
Jakub Zych
3ecbd1f711