need title insurance if house has had a warranty deed?

[Jill Curran]

Newbie here. I'm looking at a bank-owned house for auction on auction.com. I can see in county records that the last owner got a warranty deed in March of 2017, and then it went back to US Bank with a mortgagee's deed in November 2018. Here are my questions--doesn't the fact that he could get a warranty deed mean the title was clear up until then? Since it just went back to the bank after him, is it not still clear and therefore no need for me to purchase title insurance?

Thank you for any help!

Jill