an odd problem with UV's


i’ve run into an odd issue with a model i’m creating. maybe someone has seen this before.

i created this model in 3ds max and imported into Mudbox. when i unwrap in max it looks fine in Max, but once i bring it into Mudbox i see these holes in my uv’s.

i have this issue with low-poly models sometimes and i’m stumped.

the particular faces are unwrapped correctly in my uv editor


oddly enough the same model with same uv’s works perfect in Mudbox 2016 (previously done in 2015)

hmmm. seems odd