So I was just troubled for about 5 hours trying to figure out why my AI stopped perceiving my player (stopped perceiving everything altogether), but i finally found the cause of the problem.
If my landscape (and corresponding AI and nav mesh) are around -1000 - 0 the AI does not perceive anything, but if I raise the landscape it functions as expected.
As you can see in these 2 pictures, the first, I am not being perceived by the AI, in the second, I am. The ONLY difference is the Z value in the transform. There are no level blueprints affecting this either.
EDIT: Coming back to it after having saved it with everything at a higher height, it seems like adjusting it now I am able to put it to any height and the perception works. But, in the process of debugging I did close and re-open the project multiple times, rolled back to previous versions of the AI and player class, just to make sure I didn’t break anything, but ultimately it was rolling back the level that solved the glitch, simply because the previous version of the level was at a greater height (z value). And indeed, in my testing earlier, AI perception was failing to recognize any type of actor (tested on 2 different landscapes, both < 0 in Z, which was remedied when I brought them up a few thousand cm
