Adobe dimension rendering Issue (Jagged Artwork)

the design looks that way because the art is being stretched across the model so its a user mistake and prob fixable

if you work in vectors then I would output your design as a Png first before bringing it into Dimension... If Bmp then export the Uv map with art attached and replace the artwork in Photoshop

you could also share the Dn file for help from fellow users but I'm not able to test Dimension issues anymore