I’m getting this strange artifact now while using render to texture, it seems to be fairly random in terms that its not happening on all of my models, but it is consistant across renders (re-rendering model will return same problem no matter what my settings are it seems)
you cant have two of the uv shells overlaying eather. So even though the uvs are properly unwrapped you must have all of the in their own space.
P.S. setting ray bias to 0.01 may also help