I have a power supply board using a dsPIC33EP processor. The firmware runs fine for hours on end, but occasionally hangs, which appears to be caused by a soft trap caused by the Auxiliary PLL going out of lock. Does anyone know how to deal with this? Can I reinitialize the clock and continue? Why would the PLL be going out of lock?

The firmware drives a simple power supply, controlled over modbus. It's not related to switching spikes from the PSU as the fault occurs while the PSU is not activated. I set up the clock using MCC so the processor clock is 30.401MHz and the Auxiliary clock is 117.92MHz generate auxiliary clock at 117.92MHz. Why is it losing lock - have I configured it wrong? Can I recover from this kind of fault? I'm not finding much online about this.