Crosshair Glitch

When I started up the new snapshot in full screen mode, the crosshair looked a little glitched up.

I thought and expected that it wold look the same as usual.

What actually happened was the crosshair look a tad bit glitched up.
half of the crosshair is bigger and a little waked up.

1.Open Minecraft Snapshot 18w09a.
2.Open a world in that version.
3.Go in full screen mode.