1. Please confirm that the I2C time sequence is correct. The sequence from the datasheet is included below:
2. Please check the voltage level of the I2C lines. The microcontroller is typically 1.8V logic but MAX1036 is supplied via 5V. The minimum input high voltage of MAX1036 is 0.7*Vdd = 3.5V. If that's the case, a level translator between the MCU and the MAX1036 would be required.