To repro: Make a Custom Event node that takes a few variables with multi-word names. Copy node and paste it back into same BP and you’ll see it has messed up names. If you paste into a different BP it also messes up names in a different way (not shown here.)
Thanks for report! I was able to reproduce this in 4.6.1 and up, and have entered a bug report in our system (UE-9106). It appears that putting a space in input names is what is causing problem, so for now you can simply use “StopAngle” instead of “Stop Angle” to avoid this bug. You can also delete extra inputs in copied node. I’ll let you know when I see an update on bug. Thanks again!
Just wanted to let you know that this has been fixed internally, and fix should be integrated by 4.8. Thanks again for your report!