One hour ago I've sent a transaction to a friend with 110 sat/byte. After 30 min I've noticed that the transaction has 3 confirmation with this low fee and the network congestion.

The receiver has a Segwit address, I know that has no effect so why this get confirmed when transactions with higher fees take longer?

https://bitcoinfees.earn.com/api/v1/fees/recommended Says that recommended fees are {"fastestFee":660,"halfHourFee":660,"hourFee":590}