Another spackle question

No, no, that's not what the problem is. Humm... it's hard to explain exactly what is happening. It's like there are two different kinds of spackle going on the wall. The first one being harder then the second one so when trying to blend, the harder areas stay solid. I don't know how else to explain it.

I will try to take a picture but I don't think it will show being all white.

I am repairing cracks in my 12 yr old modular home from settling.

Metal corner beads popped and wall board shrunk back so I screwed corners back down, then spackled tape along line and blended into the wall.

Ceiling cracked so screwed wall board into wood supports placed in attic, however, ceiling no longer matched so I peels off exsisting tape, shaved a little wallboard and retaped but had to again blend spackle on one side to make it even.

Product is from Lowes. USG lightweight, all purpose joint compound.
Humm... didn't notice the lightweight before but that still shouldn't make it different textures as I am trying to work with it, would it?

I tried to take a picture but it didn't work.

I make sure I give it enough time to dry (sometimes can't get back to it for days) I used another brand to fix my livingroom and didn't have any problems so I think you may be right that it is the spackle. Didn't know there were different kinds. Sigh...