I have tried every combination of collision/generate overlaps/simulate hits/simulate physic but i can not get overlaps or hits to fire from cpp. I even added code for oncomponentbeginovelap in cpp but it has the same issue.
The only thing I could get to work is if I added a capsule to my projectile, then i did see overlaps fire.
I zipped my project to you yesterday on your google form. username chris_parello.
I also tried everything listed here Hit Events not firing
In addition every time i close and open my project all my blueprints lose their parent and i have to compile then goto each child bp and right click then asset actions reload to get them back, but its a pain because they all disappear from the world.