The recommended power-up register-programming sequence for the MAX2871 is as follows:
0x05, 0x04, 0x03, 0x02, 0x01, 0x00, WAIT 20ms, 0x05, 0x04, 0x03, 0x02, 0x01, 0x00.
Below is a screenshot correcting the power-up register-programming sequence found int he MAX2871 datasheet: