Between SW and ESB, I only recall Luke encountering Obi Wan in a dream state as he lay in a deep coma/state of shock caused by inadvertently touching Vader’s mind in his first attempt at meditating.
I recall Luke also receiving advice from a spectral Obi Wan before his battle with Baron Tagge. But as I pointed out to Screams, I’m not comparing the lessons or powers themselves to the official canon - I’m merely pointing out that it was a reasonably safe assumption (especially given how tied Marvels’s hands were legally) that Luke continued to train between movies.