Gaps with multiple layers?

On some lines there are gaps or the renderer renders too much of the next tile, I don't know how to describe this:


(first line in the log and under the player)

I initialize the console like this:
```rust
let font = "terminal8x8.png".to_string();
let context = BTermBuilder::simple80x50()
.with_font(font.clone(), 8u32, 8u32)
.with_sparse_console(80, 50, font.clone())
.with_sparse_console_no_bg(80, 50, font)
.with_title("vortex")
.build()?;
```

Any idea how this happened?
On a side note, I don't know exactly what I'm doing there with no_bg, I just needed two console layers and this looked like it worked.

Edit:
It looks fine when I don't scale it, but when I resize the window to some resolutions, it shows these artifacts on some lines.