My supervisor misjudges my knowledge
More years ago than I care to remember, I changed departments and started working for a new manager (NM). At the same time, another person (AP) also joined the department. My new manager put a weekly meeting on our calendars for the three of us. We would go into the meeting, and NM would start asking us what seemed to me to be really simple questions - what are we working on, issues with deliverables, who are we talking to about whatnot. Really simple questions. Almost insultingly simple questions, or so it seemed to me. Hey, I'm experienced and know what I'm talking about!
I started getting irritated by this meeting wasting my time. I could have had a meeting with NM to say it was wasting my time and why am I invited. Or, as I did, I took note of what was asked and what the answers were expected to look like (yes, there is problem A, we are trying fix B, and I'm working with so-and-so on alternative path, will know next week how to resolve). Then, I went 100% prepared to perform the data dump that NM seemed to want, whether or not I felt it was appropriate.
Fast forward 2 weeks, where I had started off the meetings presenting the necessary information (and only the necessary information) to NM at the beginning of the meeting in ~ 5 minutes. No questions addressed to me. Then, AP would get questioned, and generally fumble through the answers and need direction on what to do next.
Next week, I was removed from the calendar invite. AP was not.
Several months later, NM and I had a nice conversation over lunch about the purpose of the meeting. Basically, it was to establish that (1) I knew what I was supposed to do, (2) who I was supposed to work with, (3) I could rapidly summarize progress/goals/deliverables/budget stuff, and (4) I indeed could think for my self and be proactive in getting the right things done. In essence, I had passed the test and shown that I was, indeed, and as expected, an independent contributor and good team player. And, NM remained a good manager and mentor for me, just much more hands off (unless needed!).
What does this mean for you? You started a few weeks ago. You and your work style are a complete unknown to your advisor. What do they really want? What questions do they ask? Can you anticipate what they are and how to answer them correctly? If you need help, do you ask for it? Can you describe what you are working on in 60 seconds or less?
Be proactive. Show that you do indeed know the right things and are applying them properly. Do not go there to passively answer questions. Ask for help when you need it. And, learn to deal with people whose social interaction style is that way - you will meet many more in the course of your career.
As a supervisor, I gain confidence in my students' skills when they start producing results. "Discussing new ideas" may or may not be an indicator of understanding. A piece of working scientific code (even a short one), a fully worked out problem (even simple one), a nicely produced graph/visualisation (even a simple one) often say more than thousand words.
I've had similar worries. Rushing too far ahead too quickly can be seen as showing off, which some will not digest well and will react with throwing basics at you back.
Having blasted my way through a similar period (I was rushing ahead) in the not too distant past, for me it slowly worked out for the best. Once I've proven that I "master" the basics, the discussion progressed to a really good intellectual level, in which both supervisor and me would freely admit what we know and what we don't.
Looped advice across meetings can be politely solved by taking meeting notes. At the next one, you can always pop up and say, "Based on the previous discussion, I have already looked at X and ... [invalidate politely] or [validate]". This will show that you've done your homework, and can move on.
Obviously this depends a lot on the person. Disclaimer: this was also during the course of a PhD degree, not a master's. I know it's not an easy advice to follow -I almost failed at it - but patience, if you can afford it, works well in this scenario, especially if your supervisor is relevant for your subject.