If you renew your learner permit (your 2nd), it will last for 2 years. Before you'll be issued with a third or subsequent permit, you will have to provide evidence that you've applied for the Driving Test or have done the test and failed it.
If you don't renew your licence within 5 years, and then apply for a learner permit, you'll be treated as a first-time applicant, and will have to take the theory test and probably the CBT.
If you renew within 5 years, you won't have to re-sit the theory test and you won't have to take CBT.