I have an issue with linework being partially hidden behind a model. I have arranged the layer so that the linework is sitting at the front and the model sitting at the back, but its still obfuscated. It’s also impossible to select the lines (rectangle) without moving the model out of the way.
I’ve experience this issue with another model in the same document, but there it was an issue with a duplicated model (that was sitting exactly on top). It’s not the case here though. I’ve pasted a screenshot below.
You mentioned trouble selecting when other items are behind it in the same layer. Remember you can move things vertically to avoid that problem. I was having the same problem making scenes until DaveR recommended that I move the scenes up.