AD9371 Mykonos Charge Pump Error

I am developing a setup using a custom AD9371 board with the ZC706 for the baseband processor.  On some units, I intermittently get the following debug message during configuration:

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clock locked
BBIC JESD204B Initialization
Mykonos Initialization
MESSAGE: 0: MYKONOS_resetDevice()

MESSAGE: 0: MYKONOS_initialize()

MESSAGE: 0: MYKONOS_verifyDeviceDataStructure()

MESSAGE: 0: MYKONOS_verifyProfiles()

MESSAGE: 0: MYKONOS_setSpiSettings()

MESSAGE: 0: MYKONOS_initDigitalClocks()

MESSAGE: 0: MYKONOS_calculateScaledDeviceClk_kHz()

MESSAGE: 0: MYKONOS_waitForEvent()

WARNING: 233: Clock PLL Charge Pump Cal event timed out in MYKONOS_waitForEvent()

Clock PLL Charge Pump Cal event timed out in MYKONOS_waitForEvent()

MESSAGE: 0: MYKONOS_checkPllsLockStatus()

PLL not locked

As this does not happen on all boards or consistently on all power ups, what should I look at for troubleshooting?