upstairs is constructed of 14" TJI floor joists, 3/4" T&G OSB and has 1/2" drywall attached to bottom - the floors sound like rice krispies - not your typical floor squeak or nail pop from a wall plate - it is a crackling sound
'
thoughts?

How new is the construction, what climate are you in, and what was the weather when it was built?

Could be expansion/contraction.

Less than a year, South Carolina high humidity, osb got wet during very rainy time here, however, we have already cut out the OSB in worst room and replaced with new, added osb scabs sandwiched on I joists, shimmed wall to bottom of joists, glued shims and glued drywall to I joist - this did fix that area, however; I'm trying to figure out why this is happening as we build over 200 homes a year in this area the same way and have a handful with this condition

Very expanded lumber when you built, perhaps, now trying to shrink.

Understood, however, with the amount of homes built at the same time and under the same conditions just trying to understand why this house is doing this
Thanks for the response

Then check who on your crews worked on those houses. Someone isn't doing expansion joints right.