Something weird is happening with airline pricing

I'm researching some flight options for my upcoming trip and I've been noticing some discrepancies in pricing for the same flight. A multi-city priced cheaper than a one-way I'm looking to travel LAS-SFO on American Airlines, with a layover in LAX. While the 6PM departure is only $219, the 10AM departure is at a much higher $388. While I know I can always book the later flight and standby for the…