I found a solution similar to what Quinn suggested on Google's Project Santa's github. I just ported it to swift. Here it is: let deadline = DispatchTime(uptimeNanoseconds: cMsg.pointee.deadline) - .seconds(2) let handlerSemaphore = DispatchSemaphore(value: 0) handlerSemaphore.signal() let deadlineSemaphore = DispatchSemaphore(value: 0) queue.asyncAfter(deadline: deadline) { // Check if event handler has already responded if handlerSemaphore.wait(timeout: .now()) == .timedOut { // Event handler already responded so exit return } // Deadline met, event handler still processing, default to allow self.allowMessage(cMsg) deadlineSemaphore.signal() } queue.async { // Process auth event and respond handleAuthEvent(cMsg) // Check if deadline was met if handlerSemaphore.wait(timeout: .now()) == .timedOut { // Wait for deadline block to allow the message, then free deadlineSemaphore.wait() } self.freeMessage(cMsg) }

After many tests I finally found a solution. Apparently the & at the end of the command is whats causing the issue in Sonoma. So I had to replace this command: /Applications/myapp.app/Contents/MacOS/myapp --load-system-extension & With this one: /usr/bin/open /Applications/myapp.app --args --load-system-extension And now it works perfectly! Im still curious about those better ways to activate an extension.