Yep again, I think I solve the problem.

Lefty use Target Point to move..

..And one thing I never thought about was that there is an "Acceptance Radius" for these points. And I set them to 0. Big mistake as Lefty couldn't reach them. I set them to 1 and from what I can see on Unreal, he can now navigate the place

Sorry Everyone for the delay and the spam of devlog recently. (I work alone so.. It's quite difficult to work alone )

I reaaaaly hope this version is the good one !