Horizontal vs vertical lines. Is this normal?

I received my first laser last week. I bought this because I want to etch pcb. I bought the Jinsoku LC-40 with the 5.5w compresses laser module because the laser spot would be a lot smaller (0.08*0.05).

I went to do some tests and I have my doubts about the laser module. The horizontal line is 0.3mm instead of 0.08.

but what I noticed later is that (on different material) the horizontal line seems to engrave deeper.

Is this normal?

Thanks in advance.