check that your task are enqueued in the queue the agent is listening to.
from the webUI, in your step's task, check the default_queue in the configuration section.
when you fire the agent you should have a log that also specifies which queue the agentis ssigned to
finally, in the webApp, you can check the Workers & Queues section. There you could see the agent(s), the queue they are listening to, and what tasks are enqueued in what queue