When operating the voltage between pin 1 and 4 of the MAX31855T on the breakout board is 3.109 V, which I think is just within the recommended operating range of the chip as per spec sheet (3.0v to 3.6v). Im feeding the breakout board with 5.06v from Vcc on the Arduino so I guess there must be a voltage regulator on the board.
But are there also level converters on the board for the signal lines? And how stable is the power supply? It seems that several people are experiencing the same problems, so I would guess that this board is badly designed. The more direct your access to the chip is, the better the datasheet will tell you how to operate. If you have circuitry in between, you should have the schematics to know how these components might behave.