[Old Thread] Unable to kill the architect

July 2021.  I don't know if I ran into the same bug as other people, but after failing miserably at this fight at lower levels, I can back to it at level 50+ and though I could breeze through it in EOS and found the issue where I have destroyed all three leg targets, but the head won't open and let me finish it off.  After running around dodging for 10 or 15 minutes, I said screw it and ran right up close to the thing using my engineer evade.   Once I got real close, the head opened up, and I was able to close cover and take it out.  So if you are having issues with this still, try closing in to uncomfortable range to get its attention, and then seek cover and shoot.