Which date is used to add learners to the learning initiative

We have a learning initiative set up that assigns required learning to all new starters with a due date of 30 days from joining.

We have a learner with a hire date of 2nd September 2024 but was created on the system on 22nd July 2024.
Her learning is showing a due date of 22nd August 2024 when we would expect it to show as 2nd October 2024.

Please could you advise this is expected behaviour?

Thanks