How to use Line Of Sight properly?

I've got a bizarre problem in my project. I'm trying to use the Line of Sight behavior to make some rotating cameras that will spot the player. Seems simple enough. But sometimes (about 80% of playthroughs), the "Has Line of Sight" condition will never be true.

The behavior's obstacles mode is set to Solids, and I've got one big tilemap covering the entire layout where I fill in any square that needs to be solid.

Does Line of Sight have any known bugs with solid tilemaps?

I don't use Line of sight, i just use invisible sprite and when the player overlap it the camera will trigger.

This easy to use also great for the performance.

That makes a lot of sense, actually. I think I will try that.

Thanks!

Edit: Tried it and it works. Still wish I knew what was wrong with Line of Sight, but at least I can continue with my game now!