Conversions have a 5 year rule even after 59.5.
https://www.investopedia.com/ask/answers/05/waitingperiodroth.asp
From the article:
Can You Take Money Out of a Roth IRA Before 5 Years?
The Roth IRA five-year rule says you cannot withdraw earnings tax free until it's been at least five years since you first contributed to a Roth IRA account.1 This rule applies to everyone who contributes to a Roth IRA, whether they're 59½ or 105 years old.
Does the 5-Year Rule Apply to Roth Conversions After Age 59½?
Yes. Even if you're over age 59½ when you withdraw, some of your withdrawals could get included in taxable income, thanks to the five-year rule. You won't owe the 10% penalty in that case, but you'll still owe tax on any withdrawals above the amount contributed.1