How long after making a Voluntary payment

My wife paid for one of her missing years online around 10 days ago. She received a receipt email. However, the missing year is still showing on her online page. I was wondering how long before her page will be updated.

Hi Colin Clarke,
The current timescale for allocating your wife’s payment is approximately 36 weeks from the date of receipt.
The department who will allocate the payment are currently processing work with a receipt date of 4 November 2023.
Thank you. 

Thank you. Wow! that's certainly quite a backlog. Not very helpful given that there is a time limit on making these payments.