In base you have 3 'things' to deal with.
1/ The behaviors are developed in times that devices could not run html 5 at a decent performance. And we are still locked up in that paradigm. I feel like it is time to move on, but i dont know that. As a result, .... all behaviors are optimized in an awesome way (i can only give compliments about that) ... but also to a point that any change will break compatibility with older versions of construct 2. That is why most behaviors are pretty basic.
Escape is possible, but you have to re-code it all yourself and accept a drop in performance in a lot of cases.
There are 3th party behaviors that are made outside of that paradigm. Like the one that i am using in my example.
2/ The LOS behavior only checks if the origins are visible. This for obvious performance reasons. I wish Ashley would make that paradigm shift, but i guess either Ashley or our devices are not ready for that. So, even if you would manage to get it working with LOS, it will not solve your problem.
3/ Since the LOS behavior only checks for the visibility of the origins, but the obstacles act as volumes, adding an instance as obstacle .... will obscure its origin from the LOS. So, there is no solution for an instance to be an obstacle (an obstacle = its collision polygon shape) and at the same time to be a target (origin is inside the polygon shape).
Taking in account all the above, i made you a working example using a 3th party plugin.
https://www.dropbox.com/s/trz1xmjq6wscv ... .capx?dl=0