LT3845 Multiple top FET pulses in switching cycle

In using the LT3845 for synchronous buck converter the top FET is turning on and off twice in each switching cycle.  When the top FET is turning off, it is off for exactly 1us and the bottom FET does not turn on (the gate for the bottom FET is held low), but a freewheeling diode conducts in for the 1us when the top FET is off.

Pending on the input/output conditions, this 1us gap moves within the switching waveform, but it is always present.

I do not know how the LT3845 would do this, as if the device intended to turn off the top FET, it should turn on the bottom FET after a deadtime of 0.2us.  Not shown below, but the top FET gate drive does go low from the IC during that 1us, but the bottom FET gate drive never turns on.  

Any thoughts on what is causing this to occur?

Below is a scope shot of the inductor current and bottom gate drive: