Once you see that an answer is not serving its question properly anymore, it should be tossed away. It's just their natural life cycle.
They usually kick and scream, raising one hell of a ruckus when we ask them to leave. Especially when they have been with us for a long time.
You see, too many actions have been based on those answers. Too much work and energy invested on them. They feel so important, so full of themselves. They will answer to no one. Not even to their initial question!
The hardest thing about customer interviews is knowing where to dig. An effective interview is more like a friendly interrogation. We don’t want to learn what customers think about the product, or what they like or dislike — we want to know what happened and how they chose... To get those answers we can’t just ask surface questions, we have to keep digging back behind the answers to find out what really happened.
The trick to get around this is to move smoothly up and down the gradient of social interaction intensity, never dropping below a basic floor of presence: the sense that there are other people in the same place as you.
Instead of having two modes, “in a call” and “on my own,” we need to think about multiple ways of being together which, minimally, could be:
In a video call
In an anteroom to a video call, hearing the sound of others
In a doc together
On my desktop but with the sense that colleagues are around
And the job of the designer is to ensure that their software ensures the existence of these different contexts, instead of having the binary on-a-call/not-on-a-call, and to design the transitions between them.