Where can I see a detailed interest breakdown for my RSA?

You can find a detailed interest breakdown in the app:
Finances -> select your RSA -> Interest breakdown.

The detailed breakdown summarizes the base interest and the fidelity premium we have already paid. It also shows the status of any future fidelity premiums that you are on track to earn if you don't withdraw money from this account.

The fidelity premium already acquired is deposited on your account on the first day which follows the quarter during which it has been acquired, i.e. on 1 January, 1 April, 1 July, or 1 October, or upon closing of the account