dnd 5e – Ranger Natural Explorer

The rule in the PHB states : (emphasis mine)

While traveling for an hour or more in your favored terrain, you gain the following benefits:

The way I read this and how it should be played RAW

When a party with a ranger in his favored terrain starts travelling, the first hour of travel the feature is not active and will activate only starting at the 2nd hour of travel. So they could become lost during the first hour of travel if the navigator fails a survival check. If they stop travelling for some reason, they then need to again make survival checks for the first hour and then Natural Explorer will quick-in again at the 2nd hour.

Is that correct (as per RAW playing mode) ?

NOTE: We are not playing with UA rules.