Please take into account that the continuity of the PT/ST didn’t exist when these scenes were created.
In ROTJ after Luke turns himself in on Endor, Vader admires his lightsaber saying “I see you have constructed a new lightsaber. Your training is complete” This would mean that constructing a lightsaber requires use of the Force: they cannot be mass-produced, and such control of the Force is only achieved toward the end of a Jedi’s training. More importantly, it also shows how little Vader understands about becoming a Jedi; in ANH he says to Obi-Wan “I was but the learner now I am the master”. And in ROTJ on Dagoba, Yoda tells Luke that he’s learned all that he needs to know and Luke says “So I am a Jedi” then Yoda says “No, first you must face Vader”. So basically Luke has completed the classroom part of his Jedi training but becoming a Jedi requires an inward personal journey that’s emotional and spiritual. Vader doesn’t seem to understand this and may be under the impression that the classroom training is all that’s needed.