Can't start PHQ mission - SOLVED

[Blackmath7]

Been really struggling to find a solution to this. Went to 100s of sparkles but never go the mission. Turns out it was because I had rebound the "F" key to strafe down. Therefore whenever I went near the audio signal, I didn't get the prompt to hit F. Reset the key bindings and it all worked. Just posting this in case anyone else in a similar problem.