Facing problem with the accelerometer ADXL363.

We read accelerations on 3 axes through SPI interface from AXIS DATA REGISTERS. 
ADX363 powered by stabilized power supply from DC / DC converter.
On the analogue power input, Vs is a filter of ceramic capacitors and ferrite bead. It works stably, sometimes a week, sometimes 2 weeks.
But, unexpectedly, the values ​​of the AXIS DATA REGISTERS registers (sometimes along one axis or along all axes!) cease to change.
We observed the hang of one and all axes.
Soft reset does not help. It helps only power off and reboot. Those. the master controller continues to read all the registers of the ADXL363 chip.
The chip accepts the reset commands SOFT_RESET 0x1F.
But the values ​​of the acceleration registers seemed to be frozen at the same level until the chip was completely turned off and on.

Tell me in which direction I can look around for this problem?
Why the values ​​of the registers AXIS DATA REGISTER can stop changing?