First time posting, I really need help with this problem. I’ve created a room and for some reason when I move the uv map verts for the bottom of the floor, the verts on wall4 move. and when I move the verts on wall4, the verts on the bottom of the floor move!
Example HERE: https://i.postimg.cc/nV5h7djh/halp.jpg
(wall4 is the one with a giant 03 on it)
Can anyone help?
you probably haven’t properly separated the shells into SEPARATE islands yet, is all.
Or could be due to thw way you select a vert in the viewport, even tho the UVs are properly separated, if you select a vert in the viewport by clicking it…it may equate to 2 verts in the UV editor.
or just upload the file, save ppl from wasting time trying to second guess your specific scenario.
If the floor and the walls were UV mapped together and share verts, they have welded UV’s. You need to ‘break’ or ‘detach’ those floor faces.
I think you can right click to get a quad menu for those options. If you’re doing a lot of UV’s I recommend setting a hotkey as it’s one of the most use commands.
I prefer just ‘b’ and ‘d’ myself. Ctrl+B is much slower as you can’t do it with one finger. Work smarter, not harder 
Makes a huge difference when you work on models which take several days, full time to unwrap.
B is default for Bottom and you will probably have to use Ctrl+ for something - there’s no enough letters for all:)
