San Francisco to Nashville, BNA vice versa RT non stop fares in United BE (Aug-Nov) for $101

United Airlines offers round trip non stop flights between San Francisco, SFO to Nashville, BNA for $101. This is a basic economy fare that has restrictions.
Travel (Aug-Nov)
Depart SFO: Aug 1-31
Depart BNA: Aug 4-30
Depart SFO: Sep 1,5,6,7, 9-14, 18,19,21, 25,25,27
Depart BNA: Sep 6,8-12,14-19,22-24, 26,29, 30
Depart SFO: Oct 2,3,4,5,12,18,19.21, 23,24,25,26,28,30,31
Depart BNA: Oct 6-10,13-17, 2-24, 26-31
Depart SFO: Nov 1,2,6,7,8
Depart BNA: Nov 5-7, 10-13
https://www.skyscanner.com/transp…,!multiple
https://www.skyscanner.com/transp…,!multiple