@Engineer We already had a feedback assistant issue https://feedbackassistant.apple.com/feedback/16085661 I've reproduced it with the timestamps you asked for and collected the sysdiagnose log. I've added this additional info the the feedback assistant issue.

Are regular pushes working? What about standard pushes to your app (instead of PTT pushes)? Regular pushes have the same problem. I assume that the PTT is active when you're in the background? Yes the PTT channel is active. What happens if you foreground your app? Same problem in the foreground Have you collected a sysdiagnose of the failure? Yes I have collected a sysdiagnose and have attached it to the feedback assistant issue. https://feedbackassistant.apple.com/feedback/16085661

@DTS Engineer I've raised an issue about the late date delivery here: https://feedbackassistant.apple.com/feedback/16473208

Hi, Thanks for your reply. We hadn't realized that the APNS sandbox is expected to be lower reliability/performance. Obviously our actual customers are using the production environment. After testing with the production environment we are unable to reproduce this issue. This puts our minds at ease. Thanks for your help.