So I just tested your original graph (never tested it originally)… it worked perfectly for me, lol.
Here’s the graph:
There’s a character check (which should work for both player & ai), but it even worked without it. Having the character check may solve your problem, but idk.
I tested the triggers using print string, and BeginOverlap only fired when I was in the box, and EndOverlap only fired when I exited. So idk why yours doesn’t do the same. I’m on version 4.20 and used the default third person character.