Mantis door won't open on Bogano.

I am playing the story for the second time, using New Game+ (and I am quite disappointed by the way, but this is not the point here). Anyway, I found myself in your same predicament (unable to get the door of the Mantis opened at all), until I discovered that I had to do one last thing on Bogano (first travel at the beginning). Wouldn't know how to describe the location - possibly 'Bogdo Sinkholes' within Bogano - but there you have to 'meet' again with Master Eno Cordova, who tells you about Dathomir and the Zeffo. Up until that point, should you get back to the Mantis you are not able to leave the planet as we all have witnessed, since not doing this encounter with Master Cordova would be an essential missing (so important that, as said, Cal wouldnt' be 'allowed' to leave the planet in the first place). This is what I have just understood. In fact, once I (as Cal) had "talked" to Cordova telling me about the Zeffo and Dathomir, I have been able to reach the Mantis, get inside and chose what planet to visit using its holotable.

Hope I have been of some help.