I am having very regular (once every 5 minutes) full system freezes on my new iMac. I have contacted apple support over the past few weeks but I have not gotten anywhere. My Mac freezes when connected to an external display when using safari (the last 6 times it has frozen I have been using safari at the time). The screen goes blank (backlight still on) then the computer restarted after ~ 60 seconds and I get the following error message when I log back in (See below) iMac (Retina 5K, 27-inch, 2020) Processor 3.8 GHz 8-Core Intel Core i7 Memory: 40 GB 2667 MHz DDR4 Graphics: AMD Radeon Pro 5500 XT 8 GB Can anyone help me to understand the report below and figure out what could be causing this? panic(cpu 6 caller 0xffffff801d753a13): userspace watchdog timeout: no successful checkins from com.apple.WindowServer in 120 seconds service: com.apple.logd, total successful checkins since load (1310 seconds ago): 132, last successful checkin: 0 seconds ago service: com.apple.WindowServer, total successful checkins since load (1280 seconds ago): 116, last successful checkin: 120 seconds ago service: com.apple.remoted, total successful checkins since load (1310 seconds ago): 130, last successful checkin: 0 seconds ago Backtrace (CPU 6), Frame : Return Address 0xffffffb5503d3670 : 0xffffff801a4bc66d 0xffffffb5503d36c0 : 0xffffff801a5ff073 0xffffffb5503d3700 : 0xffffff801a5ef6aa 0xffffffb5503d3750 : 0xffffff801a461a2f 0xffffffb5503d3770 : 0xffffff801a4bbf0d 0xffffffb5503d3890 : 0xffffff801a4bc1f8 0xffffffb5503d3900 : 0xffffff801acbee84 0xffffffb5503d3970 : 0xffffff801d753a13 0xffffffb5503d3980 : 0xffffff801d7536ba 0xffffffb5503d39a0 : 0xffffff801ac460ee 0xffffffb5503d39f0 : 0xffffff801d752b0a 0xffffffb5503d3b20 : 0xffffff801ac502bb 0xffffffb5503d3c80 : 0xffffff801a5aaa61 0xffffffb5503d3d90 : 0xffffff801a4c1d77 0xffffffb5503d3e00 : 0xffffff801a4985d5 0xffffffb5503d3e60 : 0xffffff801a4afb82 0xffffffb5503d3ef0 : 0xffffff801a5d3823 0xffffffb5503d3fa0 : 0xffffff801a462216 Kernel Extensions in backtrace: com.apple.driver.watchdog(1.0)[7948A279-A8B8-3650-AFBF-B1E3EB68942A]@0xffffff801d752000->0xffffff801d753fff Process name corresponding to current thread: watchdogd Boot args: chunklist-security-epoch=0 -chunklist-no-rev2-dev chunklist-security-epoch=0 -chunklist-no-rev2-dev Mac OS version: 20B50 Kernel version: Darwin Kernel Version 20.1.0: Sat Oct 31 00:07:11 PDT 2020; root:xnu-7195.50.7~2/RELEASEX8664 Kernel UUID: 84C6DC45-6B02-335F-9439-5D2A9BC385A4 KernelCache slide: 0x000000001a200000 KernelCache base: 0xffffff801a400000 Kernel slide: 0x000000001a210000 Kernel text base: 0xffffff801a410000 _HIB text base: 0xffffff801a300000 System model name: iMac20,1 (Mac-CFF7D910A743CAAF) System shutdown begun: NO Hibernation exit count: 0 System uptime in nanoseconds: 1312575642395 Last Sleep: absolute basetsc basenano Uptime : 0x000001319b9adffb Sleep : 0x0000000000000000 0x0000000000000000 0x0000000000000000 Wake : 0x0000000000000000 0x00000012c54de0a8 0x0000000000000000 last started kext at 560912607718: >usb.!UUserHCI 1 (addr 0xffffff7fb9fef000, size 98304) last stopped kext at 779652293646: >usb.!UUserHCI 1 (addr 0xffffff7fb9fef000, size 98304) loaded kexts: @filesystems.smbfs 3.4.1 !ATopCaseHIDEventDriver 4000.27AudioAUUC 1.70!AHIDALSService 1AGPM 119!APlatformEnabler 2.7.0d0X86PlatformShim 1.0.0!AUpstreamUserClient 3.6.8 @kext.AMDRadeonX6000 4.0.0 @kext.AMDRadeonServiceManager 4.0.0!AGraphicsDevicePolicy 6.1.27 @filesystems.autofs 3.0 @AGDCPluginDisplayMetrics 6.1.27pmtelemetry 1LuaHardwareAccess 1.0.16 |IOUserEthernet 1.0.1 @fileutil 20.036.15 |IO!BSerialManager 8.0.1f5 @DontStealMacOS_X 7.0.0!AHV 1!ADiskImages2 1!A!IKBLGraphics 16.0.0!A!ICFLGraphicsFramebuffer 16.0.0!ABridgeAudio!C 100.2!A!ISlowAdaptiveClocking 4.0.0!AGFXHDA 100.1.431!AThunderboltIP 4.0.3!A!IPCHPMC 2.0.1!AMCCSControl 1.14BridgeAudioCommunication 100.2!AAVEBridge 6.1usb.!UHostBillboardDevice 1.0!UCardReader 511.40.9BCMWLANFirmware4378.Hashstore 1BCMWLANFirmware4377.Hashstore 1BCMWLANFirmware4364.Hashstore 1BCMWLANFirmware4355.Hashstore 1 @filesystems.tmpfs 1 |!ABCM5701Ethernet 11.0.0!ABCMWLANBusInterfacePCIeMac 1 @filesystems.hfs.kext 556.41.1 @BootCache 40 @!AFSCompression.!AFSCompressionTypeZlib 1.0.0 @!AFSCompression.!AFSCompressionTypeDataless 1.0.0d1 @filesystems.apfs 1677.50.1 @private.KextAudit 1.0!AACPIButtons 6.1!ASMBIOS 2.1!AACPIEC 6.1!AAPIC 1.7 @!ASystemPolicy 2.0.0 @nke.applicationfirewall 310 |IOKitRegistryCompatibility 1 |EndpointSecurity 1!AActuatorDriver 4400.28!AHIDKeyboard 222!AMultitouchDriver 4400.28!AInputDeviceSupport 4400.35!AHS!BDriver 4000.27IO!BHIDDriver 8.0.1f5 @kext.triggers 1.0 @kext.AMDRadeonX6200HWLibs 1.0 |IOAVB!F 900.12 @!AGPUWrangler 6.1.27 @kext.AMDRadeonX6000Framebuffer 4.0.0 @kext.AMDSupport 4.0.0 |IOAccelerator!F2 439.35.4 @plugin.IOgPTPPlugin 900.11 |IOEthernetAVB!C 1.1.0X86PlatformPlugin 1.0.0 |IOSlowAdaptiveClocking!F 1.0.0 @kext.AMDRadeonX6000HWServices 4.0.0!ASMBusPCI 1.0.14d1IOPlatformPlugin!F 6.0.0d8!AGraphicsControl 6.1.27 @!AGraphicsDeviceControl 6.1.27 |IO!BHost!CUARTTransport 8.0.1f5 |IO!BHost!CTransport 8.0.1f5 |IONDRVSupport 585 |IOGraphics!F 585!ASMBus!C 1.0.18d1!UAudio 401.4 |IOAudio!F 300.6.1 @vecLib.kext 1.2.0!A!ILpssUARTv1 3.0.60!A!ILpssUARTCommon 3.0.60!AOnboardSerial 1.0Core!S 554usb.!UHub 1.2usb.cdc.ncm 5.0.0usb.cdc 5.0.0usb.networking 5.0.0usb.!UHostCompositeDevice 1.2!AThunderboltPCIDownAdapter 4.1.1!AThunderboltDPInAdapter 8.1.4!AThunderboltDPAdapter!F 8.1.4!AHPM 3.4.4!A!ILpssI2C!C 3.0.60!A!ILpssI2C 3.0.60!A!ILpssDmac 3.0.60!AThunderboltNHI 7.2.8 |IOThunderbolt!F 9.3.2!ABSDKextStarter 3 |IOSurface 289.3!ABCMWLANCoreMac 1.0.0 |IOSerial!F 11 |IO80211!FV2 1200.12.2b1 |IOSkywalk!F 1mDNSOffloadUserClient 1.0.1b8IOImageLoader 1.0.0corecapture 1.0.4 @filesystems.hfs.encodings.kext 1 |IOUSB!F 900.4.2usb.!UVHCIBCE 1.2usb.!UVHCICommonBCE 1.0usb.!UVHCI 1.2usb.!UVHCICommon 1.0!AEffaceableNOR 1.0 |IOBufferCopy!C 1.1.0 |IOBufferCopyEngine!F 1 |IONVMe!F 2.1.0usb.!UXHCIPCI 1.2usb.!UXHCI 1.2!AEFINVRAM 2.1!AEFIRuntime 2.1!ASMCRTC 1.0 |IOSMBus!F 1.1 |IOHID!F 2.0.0 $!AImage4 3.0.0 |IOTimeSync!F 900.11 |IONetworking!F 3.4DiskImages 493.0.0 |IO!B!F 8.0.1f5 |IOReport!F 47 |IO!BPacketLogger 8.0.1f5 $quarantine 4 $sandbox 300.0 @kext.!AMatch 1.0.0d1 |CoreAnalytics!F 1!ASSE 1.0!AKeyStore 2!UTDM 511.40.9 |IOUSBMass!SDriver 184.40.6 |IOSCSIBlockCommandsDevice 436.40.6 |IO!S!F 2.1 |IOSCSIArchitectureModel!F 436.40.6!AMobileFileIntegrity 1.0.5 @kext.CoreTrust 1!AFDEKeyStore 28.30!AEffaceable!S 1.0!ACredentialManager 1.0KernelRelayHost 1 |IOUSBHost!F 1.2!UHostMergeProperties 1.2usb.!UCommon 1.0!ABusPower!C 1.0!ASEPManager 1.0.1IOSlaveProcessor 1!AACPIPlatform 6.1!ASMC 3.1.9 |IOPCI!F 2.9 |IOACPI!F 1.4watchdog 1 @kec.pthread 1 @kec.corecrypto 1.0 @kec.Libm 1

I have created a SwiftUI app in Xcode 12.0.1 building under iOS 14. My app reads UDP data sent over a local network and for that I use the CocoaAsyncSocket library. This is an example of Server class: class UDPServer : NSObject, GCDAsyncUdpSocketDelegate { 		 		var PORT : UInt16; 		var socket:GCDAsyncUdpSocket!; 		 		init(port: UInt16){ 				self.PORT = UInt16(UserDefaultsHelper.getPort()) 				super.init() 				socket = GCDAsyncUdpSocket(delegate: self, delegateQueue:DispatchQueue.main) 				socket.setIPv4Enabled(true) 				socket.setIPv6Enabled(true) 		} 		 		func start()	{ 				do { 						try socket.bind(toPort: PORT) 						print("Socket bound to port \(PORT)") 						try socket.beginReceiving() 				} catch	{ 						print(error) 						socket.close() 				} 		} 		 		func stop() { 				socket.close(); 		} 		 		func udpSocket(_ sock: GCDAsyncUdpSocket, didReceive data: Data, fromAddress address: Data, withFilterContext filterContext: Any?) { 				//do stuff with the data } When I test the app on a physical device, UDP packets are received and the app works fine. I can close the app, disconnect the socket (calling close()), connect again (calling start()) and continue to receive packets. If I don't use the app for around 12 hours and then open it again and try to connect, the socket binds to the port but the app doesn't receive any data. Even if I close/terminate the app and reopen it, or if I restart the device, and then reopen the app, no data is received. This happens on both iPad and iPhone devices, but not in the simulator. However, if I rebuild the app via XCode and run it on my device (Product -> Run, while the device is connected) it starts to work again. Some users have said that they never receive packets, even though they are being sent over the network. I have been experiencing this on many devices, and many test flight users are experiencing this too. This did not happen when the product was built for iOS 13. What is causing the app to fail to receive packets? And why does rebuilding and running the app via XCode seem to temporarily solve this problem? I noticed that there was a similar issue reported here: https://developer.apple.com/forums/thread/662082?login=true I attempted to request the multicast entitlement from apple, but they said that it was not required as I was only receiving unicast data.