This anomaly applies to Revision 2, build codes QFAA-Bxx, QCAA-Bxx, CAAA-Bxx.
RTC registers will not contain the correct/expected value if read.
The RTC has been idle.
RTC configuration cannot be determined by reading RTC registers.
NRF_CLOCK->EVENTS_LFCLKSTARTED = 0;
NRF_CLOCK->TASKS_LFCLKSTART = 1;
while (NRF_CLOCK->EVENTS_LFCLKSTARTED == 0) {}
NRF_RTC0->TASKS_STOP = 0;