I interviewed as a single founder as well. They spent the entire interview trying to directly match my idea to existing markets. I probably appeared stubborn as I tried to explain how my idea was different.
How could I appear other than stubborn?
If they had said, OK I think we understand your idea but your market doesn't seem big enough (or something to that effect), maybe things would have turned out differently than 11 minutes of what seemed to me like "we don't get it," when they probably did and didn't believe in it.
Well, in any case, I got some good feedback and I still appreciate the opportunity to discuss my company with them.
Hindsight may be 20-20, but I still have to fend off the regret for not redirecting the conversation.
As a word of advice to future single founders, they are going to aggressively push you the entire time. Be prepared to concede to them at some point even if they don't "get it." Otherwise, you will appear stubborn.