What happened?
https://a2a-protocol.org/latest/specification/#413-taskstate has this as:
TASK_STATE_CANCELLED Represents the status a task was cancelled before it finished. This is a terminal state.
According to https://a2a-protocol.org/latest/specification/#55-json-field-naming-convention it seems the JSON payload should be 'cancelled' for this state. However, other parts of the spec still use the word 'canceled' in a lot of places. There are also several other occurrences of 'cancelled'.
Relevant log output
Code of Conduct