Smart Temperature Sensor, only exports one month of data
I have a number of Tapo T310 smart temperature and humidity sensors that have been collecting data since the start of the year. I can view the data using the Tapo application on my iPhone, with options to view the last 24-hours, last month and last year of data. I can see data in the one-year view going back to January. When I try and export the temperature data with the application's export feature, the CSV file that is sent to my email address only contains the last month of data, independent of which export date range I select. I have tried changing the export data interval (from 1 minute to 15 minutes) and tried a three month and two month export, but the CSV file always contains the last 30 days of data.
According to the Tapo T310 website (https://www.tapo.com/en/product/smart-sensor/tapo-t310/) I should be able to access and export up to 2-years of logged cloud data for free. Am I missing some step that would enable me to export my last three months of data, or is this a limitation of the iPhone application ? ?
Any advice most welcome.