On Sunday 1 September TfL noticed suspicious behavior on their network and shut many of their systems as a consequence. Unfortunately, one of these systems is a core data source for True Tube Status. As a result, the app has been showing ‘Insufficient data’ since early September. (This is still the case into October). TfL have said they will turn everything back on but aren’t giving a timeframe or details. Here’s where they’re providing updates: https://techforum.tfl.gov.uk/t/updated-24-sept-issues-with-data-feeds/3609/60