I'd first ask are these big spikes -well above your normal peaks? Or put another way- is the mix running hot enough where 'normal peaks are close to 'zero?
One of the things I like about bouncing my mixes down to a new track in the proj is you get to zero in on stuff like that and being it's aligned with the sources you just scan up above in the tracks to see where it's coming from.
Or, what combinations of things.
Every once in a while it seems there's peaks that sort of don't even follow what's above in the tracks. 'Random unhappy coincidental pile-ups? (You know like them rogue waves' they have out at sea you hear about
Why do you love them so much? Because, they stand on a wall and say nothing is going to harm you tonight, not on my watch.