Unsure how to use the selection tool, having inconsistent results due to an unknown user error.
So I'm trying to use the selection tool to move stuff around, as I do. However, on some of my layers it will select only a bit of something and will highlight it with a bunch of dots, as pictured here.
This is what I want to happen, as I find using that format is much easier for me to work with.
However, on the layer that I'm making the rough sketch on, it selects the lines like this:

I don't know how to change this, and I know that this is completely user error, but I don't know what that error is. I want to know how/if I can make the selection tool select with the dots, as that is what I know how to work with easily.
Any help is appreciated, thanks!