Most customer interviews are unfalsifiable. The customer is polite. They say things like "yeah, that could be useful" and "interesting idea" and "I'd probably use that if it existed." The team comes back from the interview with a list of features the customer might want, ships them, and is surprised when the customer doesn't use them. The interview didn't really tell you anything; it just gave you cover to ship what you already wanted to build.
The fix is to ask different questions. Three questions, in particular, that turn an unfalsifiable conversation into something the team can act on. First: "Walk me through the last time you tried to do [X]." Past behavior is much more honest than future intention. People are very bad at predicting what they'll do. They're reasonable at describing what they did. The story they tell you about last Tuesday — the actual workflow, where they got stuck, what they used as a workaround — is far more informative than any answer to "would you use this?"
Second: "What did you try before you talked to us?" If they haven't tried anything, the problem isn't urgent enough to justify them paying you to solve it. If they've tried five things and hate all five, you have a real customer. If they've tried one thing and it works fine, you might be solving a problem they don't have. The pattern of prior attempts tells you more about the willingness to pay than any pricing-sensitivity question.
Third: "What would you have to stop doing to use this?" Every new tool displaces something. A budget line, an existing workflow, a tab they keep open. If the customer can't tell you what gets displaced, they probably won't actually adopt the new thing — even if they say they will. The interview is most useful when it surfaces the real cost of switching, not just the imagined benefits. That cost is the one your product has to clear, and the customer telling you what it is, in their own words, is the most valuable thing they can give you.