Why can't I trace with a custom channel?

No additional steps are necessary. After creating a channel, one gets to choose the default behaviour - Ignore / Overlap / Block, which can then be overridden on per component basis. What you’re showing and describing here should work as is. Perhaps it’s time to look for the culprit elsewhere.

How are you calculating start / end atm?

If I trace with the visibility channel, everything works fine. But if I trace with a custom channel that I added, it acts as if its not even performing the trace. I get no results and it doesn’t even draw the debug line. All the scenery is set to block my custom channel. I’ve tried several different types of traces with the channel and none work. Is there another step to allow tracing by a custom channel after you create it?

First I tried get hit result under cursor by channel. It worked with visibility but not with my custom channel. I didn’t know why so then I used a regular trace by channel to get what was under the cursor and see the debug line. I thought the problem was the trace wasn’t hitting my objects for some reason. But then when I used the regular trace with the debug line, there was no line at all, like it was just refusing to do the trace. If I just use two set vectors for the start and the end trace, same result. I think I’m just going to trace for objects if I can’t find a solution to this.

What do you see here?

( on your ground )

My custom channels also work weird. I cant’t make reliable trace with them, but when i change line trace channel for VISIBILITY the same blueprint works just fine. And also when i change Trace response of the of custom trace channel of the ground mesh (just a square plane) from block to ignore objects stat to fall through the ground.

So now im thinking of deleting my custom trace channels and work with custom objects collisions

Did you ever work this out?