Profile performance spike - but numbers don't add up

My build is getting frame rate drops, but I can’t figure out where to go from here. 90 ms but the child items in the hierarchy don’t add up to 90, any idea where I should be investigating to get more info?
thanks!

Edit: I restarted my computer and the spikes went away, I was probably using too many resources with other apps open.

Even then, the ‘0.00’ don’t cost zero time, so there’s quite a bit of rounding errors going on.