I am using ADF to connect with APS, and I see APS uses below mentioned API to get task details.
In my APS when task gets assigned to group I see "Claim" button to claim that task. But when I try to open same in ADF I don't see "Claim" button. Basically ADF code looks for specific properties (mentioned below) in above API response..
Is this a custom ADF app or the OOTB ADF based process workspace? If it is a custom one, can you check if it is the same behaviour in the OOTB ADF based workspace which you can access at http://hostort/activiti-app/workspace? If it is, it may be a defect. FYI - you can also ask ADF questions on Alfresco/alfresco-ng2-components - Gitter for live help and chat! And there is also another forum where you may get a faster response on ADF related questions.