If/when the Internet Archive Wayback Machine is back online you might be able to find cached versions of the Askaboutmoney Deposit Best Buys threads in it for the period in question?
https://archive.org/
Savings Best Buys: There are 3 savings best buy threads on AskAboutMoney that are updated frequently. Instant Access and Notice Accounts - Lump sum variable rate savings. Fixed Term Deposits - Fixed Lump Sum Term Deposits from a few months to a few years. Regular Savings - Smaller sum...
Here are the rates from July 2021: https://web.archive.org/web/20210704100514/https://www.askaboutmoney.com/threads/instant-access-notice-deposit-accounts.102329/
The highest instant access rate, without fees, was just 0.10% from banks in Ireland back then.