Hi Cristiano,
Can you explain a little bit more what are you trying to solve doing:
"I faced this situation because I tried to update the CommandBasedWSHumanTaskHandler to not depend on a KnowledgeSession and only use the WorkItemManager received as parameter, but then some problems started to happen."
If you don't use the ksession inside the CommandBasedWSHumanTaskHandler the HumanTaskHandler will not be able to notify the session when a task is being completed, so your process will not be signaled to continue to the next node.
Greetings.