Have you had a review with this person since they started?
Have you asked them about how thy have found the training?
What they think they are doing well? What they are struggling with? Where they think they need support?
You could politely mention they appear to still have a lot of questions, and you want to help them n that regard.
Point them to various people, John is an expert on Y, Mary is very experienced at Y etc.
Tell them thst you really only have a half hour slot at X for queries etc.
Suggest taking notes etc so they have a reference point for even they have to do the same task again etc.
When asked questions, put it bscl on them, ok, what have you done so far, what have you looked up? who did you speak to? If I wasn't here today and you had to complete thecadk what would you have done? What can you do differently next time etc?
They may be afraid of making a mistake? They may be setting very high standards for themselve etc?
You need to have the conversation. Highlight what supports are available, highlight expectations etc. Review every few weeks to ensure there are improvements etc.