Why would Sweep not work at Low FPS?

UE 4.7.5 and 4.8 as well.

Hi there

I’m a bit baffled with this.
I have some fast moving object in my map that would detect when hitting the player at 60fps. But if I use the t.maxFPS command to set the framerate to 10, to test how the game behave with a very crappy machine, then the Sweep would NOT detect the player.
I was under the assumption that the Sweep was made precisely for such case.

What is confusing is that I can’t repro that in a test map. It works perfectly fine. Just… not on my project.
So, what could be causing the issue on my project and not in a test map? Any guesses?

Ps : before anyone suggests that, yes of course I did tried “Use CCD”, to no avail.

For anyone having the same issue.
The sweep works fine at low FPS, but the real issue was the sweep working only with the root component.

See this link for the actual thread.