Sprites collision with TriggerBox (or any other object) isn't working

Hi there, sorry, total newbie here. So we’re trying to replicate pong using the ue4 engine, and so far with no avail.
We’re stuck in a very early stage. It might be important to note that we have created an empty blueprint project.
Currently we have a ball, which is a blueprint of an actor and a sprite (the sprite itself is set for 3D collisions and a tight bounding collision box).
(Side question: Does the fact that our blueprint has a sprite with a collision box mean that the actor itself inherits this collision box?).
The ball’s blueprint is added as an image below.
Please note that it seems like I don’t have any collisions at all on this level, but since I’m new to this I am a bit reluctant to make that claim.

We’re trying to collide this ball with the TriggerBox. Both are set to “Block All”.
Here are the coordinates just in case:

x: -1270.0 cm
y: 10.0 cm
z: 250.0 cm

x: 100.0 cm
y: 10.0 cm
z: 60.0 cm

TriggerBox Extent:
x: 1100.0
y: 40.0
z: 650.0