yes, the conversion of the RSU to stock shares that you own is a 'buy'.
https://www.irs.gov/instructions/i1040sd#idm140099366727232
this link is not specific to your question, but you are at risk based on transaction dates only. The transaction date is the date you acquire property and sell property. The settlement date is simply the date the cash moves to cover the trade.
If I sell at a loss on 12/23/20 but it doesn't settle until 12/24/20, I am no longer at risk to the whims of the market once I sell on the 23rd. If I buy back prior to January 22, 2021 (remember December has 31 days), a wash sale has occurred, even if the settlement date is Jan 25; I am at risk based on the date I buy, not the date it settles.
you may want to read the instructions for Form 8949 as it talks about acquisition dates and dispositions dates, which are transaction dates,
