Congratulations! First, it’s not possible to set a true 20-minute and 60-minute peak within the same ride. I mean, yes, you technically did it, but if you would have gone all out for 20 minutes, your 60-minute would have been destroyed. Likewise, if you paced for 60 minutes, your 20-minute is under-represented.
So, I would actually use 105% of your peak 60, as the 20-minute is not valid, but the 60 probably is close to being valid and I’m adjusting your 60 to what a peak 30 would probably be. In other words, FTP =
100% of 30
95% of 20
105% of 60