Verbal skirmish
Jason figured out that his knowledge was at par with the questions but his understanding lagged behind and he wasn't able to comprehend every situation stated by his masters, which was only reasonable.
If he were able to answer everything after memorizing the content of the dozen books he'd read over the last month, why would he even need Shane and Dalia as his Artisan masters in the first place?
It would be entirely useless and utter waste of time.
Nevertheless, his comprehension was good but there was just too much to reconsider with every lifestyle occupation.
Jason understood the basics but concluding some facts was still extremely difficult due to his lack of practice.
Dalia and Shane also figured that out and they decided to focus on these facts while imparting their lessons.