Some years ago. I was consulting as user researcher for a parcel service, that provides parcel-automats for self-service pick-up. They wanted to improve on showing the status of occupancy of a certain automat, to indicate the likeliness of a parcel being delivered to the original automat or being rerouted.
Their data was very accurate and within a timeframe of 24h before arrival they even had real-time data on occupancy - and the means to communicate that status. What they were already doing on their website and their mobile app. Nonetheless a lot of people complained of occupied automats and being forced to claim their parcel elsewhere.
So it was assumed the way how the status was communicated would be faulty, as they data wasn't. There had to be a usability problem! Wonderful! So, I'm stepping in an setting up an interview with some prototypes of improved UIs to see, if the status would be better recognized.
My research - interviewing customers that were using the automats regularly - showed the flaw in the system very clearly: The customers just didn't believe the data to be correct! They assumed, that it wouldn't be worthwhile to check the status. They all had those stories, where they received the parcels in their preferred automat, even when it was considered occupied or got it rerouted, even when the automat was indicated to be available.
They couldn't grasp, that in 9 out of 10 cases or even more, the status was correct. The experience with the faulty delivery got stuck. Even when I told them, that the data was pretty accurate, only a few said they would consider it in the future. It seemed to cumbersome to care upfront about it - even when nearly everbody admitted to be at least annoyed, when their parcel would be redirected.
In the end I concluded that the customers would very likely stick to ignore information, just hoping for the best, as the interviews indicated, that the habit of mistrust was the issue. We would need to convinve them, to trust the status, but it was clear, that this is not just done, by improving the UI.
Eventually we found some usability improvements nonetheless, where we would add more details to the status to educate customers in the long run, that in fact they could rely on it for their decision making. Yet, it seemed only a small detail on the journey, to change customer's habits from taking their chance, to actively managing their parcels. Thankfully, the team was happy about the research - as it helped them to understand the core issue, even if I couldn't help them to just solve it by changing a feature.