What a spectacular flight that was, I don't believe they lost any of the engines, I believe they shut them down to test characteristics for engine out scenarios.
If you look at the 2 engines they used for the landing attempt, it looks like they were the 2 that went "out" during the launch.
According to Elon they missed the landing because of low fuel pressure in the header tanks but it was otherwise a success.
https://twitter.com/user/status/1336809767574982658