[CovKid66]

I'd probably delete the End Key emulation you've set up and try assigning your original action (end data connection) to a less sensitive key. It's possible that there is a slight delay as the controller tries to detect if you're actually pressing a double or triple click, and that is not playing well with the OS when it comes to the End Key specifially, and the real use of that key.

I know I had similar problems trying to reassign the Home key and it no longer performing it's original action. I ended up deleting the mapping and mapping the action to a different key.