Absolutely. That's one of the third party applications in which I have been able to reproduce the bug.

Thank you for your prompt response. In our case, we are not directly implementing WebSockets using a specific macOS API. The issue is observed in third-party applications that use WebSockets: Postman and/or Docker. In both cases, we're not directly using macOS APIs like Network Framework or URLSession. Instead, we're observing the issue in these applications running on macOS 15.0. The problem appears to be at the system level, as it affects multiple independent applications. Our Wireshark analysis shows that the data is intact when it reaches the system, but becomes corrupted when it's delivered to these applications. Given this information, we suspect there might be an issue with how macOS 15.0 is handling WebSocket connections at a lower level, which is then affecting applications that rely on the system's networking stack. Is there any additional information you need or any specific tests we can run to help diagnose this issue further?