Hello,
Repro steps:
1-In the content browser, right-click, import to, select the .usdc file, default settings, it says it successfully imported it. I view it in the asset viewer, it looks correct.
2-In Blender, I make some changes to the mesh and re-export it.
3- In Unreal, I right-click the static mesh, Reimport. It says it succeeded, but the changes are not there, it looks the same as before.
If I do the same with FBX it works.
As a work-around, I have to export it as a NEW usdc file, then right-click, reimport from new file, and select the new file.
Expected behavior: right-click/Reimport should have worked.