It feels like it has something to do with calling the stop method and not actually stopping

0 libobjc.A.dylib 0x00000001a47c7c9c objc_retain_x8 + 16 1 AudioToolboxCore 0x00000001b6a8b580 auoop::RenderPipeUser::~RenderPipeUser() + 112 (AUOOPRenderPipePool.h:277) 2 AudioToolboxCore 0x00000001b6ad8090 -[AUAudioUnit_XPC internalDeallocateRenderResources] + 92 (AUOOPRenderPipePool.mm:398) 3 AVFAudio 0x00000001c24cd0a0 AUInterfaceBaseV3::Uninitialize() + 60 (AUInterface.mm:524) 4 AVFAudio 0x00000001c2510be0 AVAudioEngineGraph::PerformCommand(AUGraphNodeBaseV3&, AVAudioEngineGraph::ENodeCommand, void*, unsigned int) const + 768 (AVAudioEngineGraph.mm:3317) 5 AVFAudio 0x00000001c251ab0c AVAudioEngineGraph::_Uninitialize(NSError**) + 132 (AVAudioEngineGraph.mm:1469) 6 AVFAudio 0x00000001c24cb834 AVAudioEngineImpl::Stop(NSError**) + 388 (AVAudioEngineGraph.mm:1455) 7 AVFAudio 0x00000001c24ca36c -[AVAudioEngine dealloc] + 52 (AVAudioEngine.mm:416) 8 TextToSpeech 0x00000001c8d87618 -[TTSSynthesisProviderAudioEngine _setupOfflineEngine] + 100 (TTSSynthesisProviderAudioEngine.m:223) 9 TextToSpeech 0x00000001c8d87c34 -[TTSSynthesisProviderAudioEngine _setupAudioUnitForVoice:remote:] + 928 (TTSSynthesisProviderAudioEngine.m:324) 10 TextToSpeech 0x00000001c8d88ac4 __55-[TTSSynthesisProviderAudioEngine renderSpeechRequest:]_block_invoke + 1640 (TTSSynthesisProviderAudioEngine.m:542) 11 libdispatch.dylib 0x00000001b2bdc320 _dispatch_call_block_and_release + 32 (init.c:1518) 12 libdispatch.dylib 0x00000001b2bddeac _dispatch_client_callout + 20 (object.m:560) 13 libdispatch.dylib 0x00000001b2be5534 _dispatch_lane_serial_drain + 668 (inline_internal.h:2640) 14 libdispatch.dylib 0x00000001b2be60d8 _dispatch_lane_invoke + 436 (queue.c:3966) 15 libdispatch.dylib 0x00000001b2bf0cdc _dispatch_workloop_worker_thread + 648 (queue.c:6913) 16 libsystem_pthread.dylib 0x000000020b0afddc _pthread_wqthread + 288 (pthread.c:2618) 17 libsystem_pthread.dylib 0x000000020b0afb7c start_wqthread + 8 (:-1)