When an automatic xCP workflow activity fails it becomes APAUSED and you can restart it using DA or API call.
However, sometimes, after restarting an activity it's marked 'to be processed by job' and waits for the job dm_bpm_XCPAutoTaskMgmt to process it after which it again becomes APAUSED.
I don't understand why it's not always marked to be processed by job although I always start the test workflow with the same parameters and it always fails in the same workitem with the same reason (method timeout).