After uvunwrap, i have Double vertices in uv editor

[falfalfal19]

Hi everyone

I have a problem in uv editor (uv unwrap). I have mark seam my object as what i need

But the problem is after i uv unwraped it. I tried to move my uv island in uv editor, but it vertices have doubled just like the following screenshot here

im trying to solve the problem like merge by distance, apply scale. And Re-Uv unwrapped again but it still same

I hope you guys have a fantastic days and wish you good health always

Thank you

[FedPete]

Vertices aren’t doubled!
It’s normal Blender behavior.
You switched on the uvmap mesh Sync selection.

[NP5]

As FedPete says it is normal behaviour.
The UV has separated out that inner ring of Faces, rather than shrink it inside as part of the bigger section. However, obviously to create the faces on the UV map when it separates islands like that there is an edge of verts that both islands need to create their outer edges. If your took away either of those ‘duplicate’ vert loops the UV would lose a whole ring of faces!
The edges of the bigger islands are actually also ‘doubled up’ for the same reason, they are the same verts in two places on the UV holding the edge of a UV face that needs defining on the UV map.

[Miss_B]

I’ve been seeing this for many versions of Blender over the years, and what I find, at least for me, is to make sure your in Poly mode, rather than Vert mode. Then the separate polys are selected without disturbing the, what I call “related polys”, that are connected to the selected poly.

That said, however, I haven’t started playing in Blender 2.8/2.9 . . . yet . . . so that may not be how to do it in the newer versions of Blender.

[falfalfal19]

Oh my i see, I’m sorry. it’s my bad

i didn’t realize that uvmap mesh Sync selection was switched on

i learn so much in here. Thank you so much everyone for your tips and helping me solving my problems