MSP430FR5969: CS module default configuration after PUC

Tool/software:

MSP430FR5969 User's Guide states under Clock System Operation on page 96, that, after PUC, ACLK is first sourced by  LFXTCLK then LFMODCLK, MCLK and SMCLK are first sourced by DCOCLK then MODCLK, because LFXT pins are not in alternative function yet.

I have a small piece of program that only configures only two pins to toggle an LED on button press with interrupt and doesn't configure anything else. But registers show that my ACLK is sourced by LFXTCLK, MCLK and SMCLK are sourced by DCOCLK when the execution is paused.

Why doesn't the mcu go into "CS Module Fail-Safe Operation"? What am I missing?