[2020] You can no longer left click the Moksha device excavation site after completing the "Fragmented Memories" Mystery.

You don't need to if you have unlocked the special research associated with it. This thing has four states:

off - click to unlock research
off - research unlocked
on - click to unlock research
on - research unlocked

If you can't click it and have not already either unlocked or completed the associated research ("Mind Your Head"), please send in a bug report. :)