Ventura 13.4 External Display Sleep Loop Bug

The Ventura 13.4 update introduced a display signal lost bug which when the monitor is put to sleep after power saving setting is reached or if manually using the shortcut keys to put sleep the display, it wakes up the monitor briefly then tries to go back to sleep for 15 seconds and then wakes up with the “no signal” warning in an infinite loop. It's starting to be reported by others, where this did not exist until after the update.

Reddit: Ventura 13.4 Display Sleep Issue https://www.reddit.com/r/MacOS/comments/13lyu2y/macos_ventura_134_display_sleep_issue/

I tried everything from turning off power saving settings, turned off screen saver, WoL, uninstalled color calibration software, reset monitor to factory settings, booted into safe mood, nothing had an effect.

Should I submit a bug report?

Doing more research, I found this in my log file when putting the display to sleep, getting repeated errors.

error 18:03:48.968770-0500 com.apple.AmbientDisplayAgent [ERROR] - Unable to create and lookup port "com.apple.CoreDisplay.master" => 1102

0 0x18d79fb58 CoreDisplay::Mach::Port::Port(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, CoreDisplay::Mach::Port::PortLookup) + 392
1 0x18d75ff5c CoreDisplay_Display_SetAutoBrightnessIsEnabled + 168
2 0x104012a44 setCompensationState + 60
3 0x104013ff4 main + 4852
4 0x18b91fe74 _xpc_connection_call_event_handler + 152
5 0x18b91e8f4 _xpc_connection_mach_event + 1376
6 0x18ba2c4c0 _dispatch_client_callout4 + 20
7 0x18ba48ed8 _dispatch_mach_msg_invoke + 468
8 0x18ba33960 _dispatch_lane_serial_drain + 372
9 0x18ba49c24 _dispatch_mach_invoke + 448
10 0x18ba3f244 _dispatch_workloop_worker_thread + 648
11 0x18bbd8074 _pthread_wqthread + 288
12 0x18bbd6d94 start_wqthread + 8

Hi, I'm the author of the Reddit post, Found the same error log on my Mac Studio.

Update: Tried to update to Ventura 13.5 Public Beta, the issue is still present.

Not much more to say besides (a) exact same problem, (b) I see the same console errors, and (c) it's infuriating, as my monitor keeps waking constantly, I have to put my Mac fully to sleep to prevent a blinding light from flashing every 15 seconds at night.

Same issue here. MacBook Pro 16 M1 Max. Please fix it.

[ERROR] - Unable to create and lookup port "com.apple.CoreDisplay.master" => 1102
0 0x191e5bb58 CoreDisplay::Mach::Port::Port(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, CoreDisplay::Mach::Port::PortLookup) + 392
1 0x191e18f88 CoreDisplay_IsCustomWhitePointSet + 100
2 0x1a8879c38 getCustomWhitePointXYZ + 120
3 0x1a887a19c modifyAndSetIntentionForWhitePoint + 68
4 0x1a887a380 modifyAndSetIntentionForWhitePointOnEveryDevice + 172
5 0x194f882d4 CGSPostLocalNotification + 188
6 0x194f87eb0 (anonymous namespace)::notify_datagram_handler(unsigned int, CGSDatagramType, void*, unsigned long, void*) + 116
7 0x194f86eb0 CGSSnarfAndDispatchDatagrams + 1108
8 0x1952c455c SLSGetNextEventRecordInternal + 344
9 0x1950bd1ac SLEventCreateNextEvent + 16
10 0x10404b7e8 main + 2792
11 0x1900e8400 _dispatch_client_callout + 20
12 0x1900f797c _dispatch_lane_barrier_sync_invoke_and_complete + 56
13 0x10404b6f4 main + 2548
14 0x1903a6254 __CFMachPortPerform + 248
15 0x190376bcc __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 60
16 0x190376aec __CFRunLoopDoSource1 + 520
17 0x1903754cc __CFRunLoopRun + 2240
18 0x1903744b8 CFRunLoopRunSpecific + 612
19 0x1903f957c CFRunLoopRun + 64
20 0x10404b4a4 main + 1956
21 0x190297fa8 _pthread_start + 148
22 0x190292da0 thread_start + 8

Took me some days to recognize that it was the 13.4 update that did let my LG 32UN880 sleep. Same problem here as described in this thread.

The only way to avoid the LG 32UN880 to really sleep is to manually put the MacBook to sleep from apple menu.

I am having the same problem. It effects the LG but not the Cinema Display. Both are connected by DP. Manual sleep does not help.

I'm also experiencing this bug after updating to macOS 13.4, but it only occurs on one of the 2 external displays attached to my Mac Studio.

The display connected to the built-in HDMI port doesn't seem to experience this, but the other display (same make/model) connected via a third-party USB-C to DisplayPort adapter does.

I have the same bug with my LG monitor.

Same Issue Two External NEC 4k's. Upon wake after forced sleep connection is lost to the externals, sometimes.

I contacted apple support and apple developer support and filed a case, so at least apple should be area of it.

Updating to 13.4.1 did nothing to address this bug. I'd have to imagine that Apple Developers are experiencing this themselves.

Update: Apple responded to the feedback I submitted on "Feedback Assistant" with "Works as currently designed."

I can't find the words to describe this garbage. It's a shame.

I have the same problem. I primarily use an LG 32UN880 on my Mac Studio M1 MAX, and a Dell 2515H as a second monitor. About a week ago I replaced the Dell with an LG 32UN880P and promptly encountered this problem. The 32UN880 always goes to sleep, the 32UN880P does not. The problem occurs via DisplayPort to USB-C cable, but via USB-C. The 32UN880P also has a MacBook Pro 13" M1 connected to it via USB-C, in addition to the Mac Studio, and the monitor does not go into standby here either. The screen is black, but the backlight stays on. It only helps to send the Mac into standby, as it has already been described by others here. I upgraded the Mac Studio to macOS Sonoma for testing, again the problem still exists.

Could someone tell which log you are viewing? Thanks!

Ventura 13.5 - bug still exist - LG 27UP850

Ventura 13.4 External Display Sleep Loop Bug
 
 
Q