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Why LTC3805-5 restarts again and again?

I have the following circuit.

The components with cross over them are not installed on the board.

I have made two boards and made a few measurement of the boards separately. Here is the result.

board #1 board #2

The result of board #1 looks OK.

The result of board #2 looks strange. It seems the soft start filter capacitor charges and discharges again and again, and the chip never works. What is wrong with board #2?