check your XSM in ld 37, stat XSM.
if your pbx health changes on active core, the cores swap.
If your ELAN to CCMS / Callpilot drops cores might switch if one core sees it before the other (active vs. inactive).
Check AHST in ld 22 to see if you are getting errors before the cores swap.
BSD alarms cause Interloop tests, maybe your DC rectifiers and or DC/AC power supply in a shelf are dying....
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