Hey @e7de84f7c71249dc8a21a7d1f05899f3!
It’s because you’re performing the traces on the Visibility channel.
Either switch it to Camera like this:
If you don’t wanna use the Camera channel, you can also create a new channel of your own from Project Settings > Engine > Collision > Trace Channels.
Or if you wanna use the Visibility channel for this task, you can select the capsule component from the Components window on the top left, then navigate to the Details window on the right side while having it selected, under the Collision section, set Collision Presets to Custom, expand it, and under the Trace Responses section, set Visibility to Block like this:
Hope this helps! 
Oh and btw, as for this one:
I get what you mean. Simply right click on an empty space on your Event Graph and search for your function like this:
There you’ll see two versions. Here you’ll wanna go with the one below (the one under Class > [Insert BPI Name]) for the target to be the interface.
You can check out this documentation for more info 
(Don’t worry about it being an UE4 documentation, the UE5 one didn’t have that info so that’s why.)
Hope these help!