"Any advice on the types of questions I should ask?"

Get the details, such as from 401(k) only? Or, was some of it from/put into a Roth? Into what type of account(s) for the from and to, and if there was/is basis, and was any converted? And get the 1099-R and also the 5498, to substantiate answers. Many 5498 came out mid-Aug, for 2020 in 2021.