What we found
This is a new construction house built next to the green belt near the Boise River. The house needed to be built above the flood plane, so the contractor built a retaining wall and back filled it with road mix then compacted it in lifts as is common and correct practice. The contractor did a great job but over the course of a few years erosion and settlement happened and the 2-story deck area settled and caused separation and heaving in the panels on the covered back patio.
