Thank you!! This was very helpful!!! Based on this, I found that the following worked for me (with no need to revert to an earlier version of MD):
If you follow the workflow that is shown in some videos online of setting up a cloth asset and then importing the USD file to it, a folder with the mesh for the clothing will appear in UE next to the cloth asset.
Go into that folder, and into the static meshes folder inside of it, double click on the mesh for the clothing to open it, and find what the material there is. In my case, it was MI_Unified_Material.
Double click that to open it, and you will find under “General” that it has “USDImportTranslucentMaterial.” Change that to “USDImportMaterial.” Click save.
Go back and open the cloth asset, and it should be ok. At least that worked for me.