Targeting bug

For some reason my “Target closest enemy” keybind has been removing it’s self . I am not exactly sure when it is doing it but it seems to be happening loading out of Delves, Instances and PVP matches. Going in is no problem but after leaving one of those events I have to constantly reset the keybind. I have never had issues prior to War Within release. Is there something with the target that is different. I know on my mage I have “Smart target” chosen but it never removed my keybind.