Agents unable to see help desk request in queue when they are added to queue using import management

We have a requirement to add agents to queues and the count is high. I used the import functionality as described in and the agents were added to the queues without any errors and I can even see them in the HR help desk queues page.

However when I log in as the agent, I'm unable to see the help desk requests present in that particular queue.

I then removed this agent from the queue and once again added manually this time. When I login as the agent this time, I'm able to see all the help desk requests assigned to the particular queue.