Hard to say for sure, this comment leads me to believe there is some sort of list of inputs that is getting modified when you plug in your controller (or already is modified when touch controllers are paired)
Hey guys! The workaround that solved it for our case at least was to unpair the touch controllers in the Oculus settings. Apparently that moves the remote back to the “top of the list” and Unreal recognizes it. I hope this was any help.