Operating system: Windows-10-10.0.18362 64 Bits
Graphics card: GeForce GTX 1080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 441.66
Broken: version: 2.81 (sub 16), branch: master, commit date: 2019-12-04 11:32, hash: rBf1aa4d18d49d
Worked: version: 2.79
Short description of error
Exporting an FBX file into Unity version 2019.2 worked with expected results. After upgrading to Blender 2.8 the model imports into Unity with many problems which appear to be hierarchical in nature. Root transform rotation has changed as well as sub-transforms that had objects attached are now in weird rotations or parented to other object in the model. textures missing (I assume due to hierarchy changes)
Exact steps for others to reproduce the error
Export the FBX from Blender 2.79 and bring into Unity. Assign textures. Re-export the FBX in 2.8 and re-import into Unity. Notice the textures are lost or re-assigned on most sub meshes.