Need Assistance: Unintended 'webServiceURL' Callback Triggered for All Apple Passes

I have successfully created an Apple Pass wallet with a 'webServiceURL' using PHP. The pass is added to the Apple Wallet successfully. However, when I sent a push notification to update a specific pass using its serial number, it worked as expected initially.

However, in the last few days, Apple has been triggering the 'webServiceURL' callback for all passes, when we trigger a push for one pass/deviceID. I'm unsure how to prevent this callback from Apple. Please provide assistance on resolving this issue.