Ok... you may think I've tried to use a glitch (that's why I posted here, hoping I'm not wrong), but KL-E-0 it's a tank. I've managed to fast travel with it without problems.
Let's start from the beginning: after reaching the third grade in Robotics Expert I've hacked KL-E-0 in Goodneighbor, hinting "Command". Even pressing O, making the four cross on the cursor disappear, I've left the place and KL-E-0 follow me outside. At this point I've fast travelled into another place (Abernathy Farm, I guess... don't remember)... noticing that the Assoultron didn't follow me. But going back, it was there... killing some gunners just out Goodneighbor, and still follow me.
The solution, in my opinion was simple: hacking another time K-L-E-0, selecting "command" and, after that, choose to click on it, just to hear my character say "wait". My idea was to let it waiting for me while doing my own thing. So I fast travelled again... after reach the new place, Kleo literally falls from the sky just in front of me saying "Good morning". This was the beginning of a whole new life in the Commonwealth.
Me, KL-E-0 and Dogmeat going around and killing every enemy we encountered: beautiful.
But there were some problems: even ordering to the Assoultron to stay there, it won't fast travel to some settlements (just like Sanctuary Hills)... so I started to deactivate it, just to be sure to find it again when coming back. Seemed to work.
But it was too much beautiful to be true... during a quest (Last Travel of the U.S.S. Constitution) I had to deactivate it just outside the ship due to K-L-E-0's hostility to the other robots (it was jealous, I supposed), and did the quest by my own.
Just after finished it, K-L-E-0 started to show some bugs... walking without a leg, or crawling with its leg at their place... then I managed to go on the Prydwen. I use the method I explain over in this post: make it wait and see if reach the Prydwen where I fast travel. K-L-E-0 wasn't there, I come back to the Abernathy Farm (where I leave it) and deactivate... just outside the settlement.
Being sure I returned to the Prydwen and took the Learning Curve quest from Quinlan, went on the bridge and... the game crushed. Problem resolution said that updating Fallout 4 or the PS4 updates would have been the best choice... but my softwares were already updated.
I load the game and... THE HORROR! WHERE'S K-L-E-0? Loading lesser recent files didn't solve anything... K-L-E-0 disappeared from my game. Not at Abernathy Farm, not at Goodneighbor, not at first location of U.S.S. Constitution, not at the Prydwen... and neither at the Boston Airport.
I'm desperate... I know that the abuse of K-L-E-0 could be a bug/glitch exploitation... but... I'm not the first one on doing this and the game allowed that.
Anyone had the same problem? Anyone had a suggestion? Tried to find something on the Internet, but nothing...
I'm really sad for not having anymore K-L-E-0 as a companion... it was so polite and kind, hoping me a "Goodmorining" and then going to burst some gunners or supermutant. And I'm even more sorry for his vendor option: my game is ruined.
Someone, please, help!