315 bus woe

Waited today at Brokenland & Hickory Ridge for the 315 bus at 5.27pm to Ellicott City. Arrived early, Google says the bus is running 15 minutes late. Then 20 minutes late. Then at 5.51pm it changes to "bus left 1 minute ago". I waited another 10 minutes before calling an uber. The bus never appeared.

What's the deal? This is my first attempt at buses in Columbia, are they always this unreliable? Where is Google getting live timing data for buses that aren't even there?