We use as content filter in our app to monitor flows, we gather data about the flow and block flows deemed suspicious.
Our content filter is activated/deactivated by a UI app but the flows are reported via XPC to a separate daemon process for analysis.
As of macOS 15, we are seeing cases where flows are missing or flows are not received at all by the content filter. The behaviour is not consistent, some devices seem to receive flows normally but others don't. It appears Intel devices are much less prone to showing the problem, whereas Arm devices routinely exhibit missing flows.
On macOS 14 or earlier, there is no sign of missing flows.
Testing on earlier beta versions of macOS 15 did not appear to show the problem, however I can't rule out if issue was present but it wasn't spotted.
Experimenting with simple examples of using a content filter (e.g. QNE2FilterMac) does not appear to reproduce the issue.
Questions,
What has changed between macOS 14 and 15 that could be the cause of the lack of flows?
Is our approach to using an app activated content filter reporting to a daemon connected via XPC unsupported?