Camunda 7.9.0-alpha2 spring boot

Long polling does not work for spring boot Camunda 7.9.0-alpha2 as expected.
API call: external-task/fetchAndLock does not wait for “asyncResponseTimeout”: 10000. It returns immediately.

Standalone (tomcat) installation waits for the asyncResponseTimeout specified. But, fetchAndLock does not fetches any tasks available during that wait.
E.g.

  1. fetchAndLock for a Topic (using Rest API) -> waiting…
  2. Start the corresponding Process in Camunda Cockpit, it shows that Process execution stops in the external task, but fetchAndLock does not return this task - still waiting…

Maven project details: camunda-archetype-spring-boot 7.8.1
pom.xml : <camunda.version>7.9.0-alpha2</camunda.version>

That is not implemented yet, see https://app.camunda.com/jira/browse/CAM-8799.