Hey @Frankiefunkin! Welcome to the forums!
There are some details that are important: What collision channel your enemy’s sight works on (it’s likely “Visibility” but it could be “Camera” or something else), and is that box a blueprint. If it IS a blueprint that makes this easy. Open the blueprint, go to the details on your static mesh and go to the “Collision” section. Make sure that is set to block whatever channel the AI is using for sight.
Also, if the foliage is working but on a different method, it would help for you to explain that because we may be able to explain why it worked for the plants and not the box. 
Hope that helps!
so the box and plants are bps. im not sure how to check what chanel the enemy sight works on im really new to using bps but im pretty sure i blocked visibility and it worked for the foliage but not the boxes
I can see in your window that your BP_BOX has a “ * “ next to it, which means it isn’t saved. That could be part of it!
Otherwise, we are going to need more information than we currently have. We need to see the blueprints, the collisions, etc before we can move forward. Pictures are worth a thousand words!
Can you open the box BP’s static mesh and make sure it has collision? Also I see you’re blocking visibility, what about everything else? Try Block on all channels! If that doesn’t work it’s probably either the way you set up vision or that the Static Mesh doesn’t have collision on it!
If the enemy can still see the player, it’s likely that the box isn’t blocking the line of sight. Make sure the box has the correct collision settings and that your enemy’s sight or visibility trace is set to treat it as an obstacle. You can also enable any debug view for the AI’s vision or line traces to confirm whether the trace is hitting the box or passing through it. That usually makes it much easier to find the issue.