There were similar reports … and it often turned out that the I2C bus got locked by some attached device (mostly it was a not-very-well-supported SFP module with DDM) … and communication between router’s management function and hardware modules was interrupted making management function to panic.
If you’re using any SFP/SFP+ modules in your switch, try to unplug all of them and see if problem persists. If it doesn’t, then plug one module at a time and check if problem re-appears … that would indicate the problematic SFP module.