Disposal and dishwasher are on different circuits but keep tripping

My house is about 5 years old and the dishwasher and disposal are on different circuits. Two weekS ago, I went to turn on the disposal and it would not turn on. I went to the breaker and the breaker for the disposal and the separate breaker for the dishwasher had both tripped. Turned them back on and everything ran fine. Since then, issue has repeated twice. At some point, when both items are off, the breakers for both trip and I have to go down and reset the breakers for both. Any idea why both are always tripping at the same time and why it is happening when neither appliance is running?