Has anyone figured out what causes this to happen and/or how to fix it.

I've had it happen a few times and have reverted to earlier saves but would like to know if anyone has actually figured out the hows and whys of this glitch.

I noticed this as well, and not just with crossbows, but other bows as well. I have no idea what causes it and it's only happened a few times, not enough to be a major aggravation (more like a minor annoyance when it happens). Would be nice to know what causes it; hopefully it isn't something that's going to become more prominent.

The only time the crosshair appeared for me was in the soul cairn