Now, I have tried looking this issue up, however most of the threads are a couple months old and have no fix or answer. Im experiencing this glitch on ps4. I seem to be stuck at 5/10 guardians defeated for the Light versus Light triumph. I know I have defested at least 3 supering guardians since then. They were roaming supers and the kill feed showed my name, so I know it was definitely my kill and not an assist. Its a bit frustrating because its one of two triumphs I still need for dredgen, and I would have been done or close to done if not this glitch.