Second you need converted vanila armor for UBE. Avaliable during instal of UBE via mod manager.
Outfits goes better with xavbio textures.
And most important. Some outfits have minor clipping, that you can adjust via outfit studio or BiggerBody in bodyslide. But if you seen an bigger issue like big clipping, or bones mistmatch, you can report it in bug section. And dont forget to screen issue and upload it somewhere like imgur.