Are you testing this in sandbox or Prod env ?
Also what is the status you seeing for the transaction .
Subscription transactions process at approximately 2:00 a.m. PST on scheduled payment dates. Therefore, the first scheduled transaction is not sent to the customer’s bank for authorization until approximately 2:00 a.m. PST on the start date that you specify when you create the subscription in your account. If you create a subscription with a start date that equals the creation date, the first scheduled payment does not process until after 2:00 a.m. the following day.
I am testing in sandbox.
I have this problem from 21th November. Every subscription from this date has not any completed payments. But today I got notifications about success payments for all subscription.
Why may be a delay in processing payment?