I found out the reason why. Still thank you to GIGA-Money, as that link is helpful!
The actor does not get spawned because the spawning location was blocked. I intentionally tested a “proper” location, but it seems like the system still didn’t like that one. I now set the Spawn Collision Handling Method to “Always spawn” and it worked properly.
I thought that the bNoFail flag would be responsible to spawn the actor no matter what, turns out it doesn’t.
My log was full because of error messages. When I scrolled up I found the message informing me about the spawn location being blocked.