WindowsServer going High CPU at specific time of day

I ended up raising a case with Apple. The only answer in Mojave is to turn off nightshift. Upgrade to Catalina fixes the issue but introduces several others. Take the pick of what is worse I suppose. Catalina works well if you don't use 3rd party apps too much. With a number of 3rd party apps I've had catalina continually kernel panic. Guess its not really ready for prime time. There are alot of others that are suffering same outcomes. However, nightshift and the CPU increse by windowserver process is fixed.

Interesting if I do a System Report and goto Sync Services my System log file from above is part of the log for Syn Services. The continued duplication of the "is implemented in " multiple places seems to be part of the detection there is a problem. Although this is all protected by SIP so it looks like its a MACOS problem as this is a clean install of Mojave.

I'm at a loss to how to further fault find this.

First, this issue only occurs if there is an external monitor plugged into my 2017 MAC at 1740. If there is no external monitor attached to the MAC there is no issue.

With an external monitor attached via USB-C/Thunderbolt 3 the WindowServer process goes High CPU at 1740 each and every day. It remains high CPU until exactly 30 minutes later at 1810. Rebooting between these times simply returns you to same position with the WindowServer Process running extremely high. Originally I thought this was display link drivers but I have proven that incorrect via uninstalling the driver and then only attaching a thunderbolt monitor to the MAC. Rules out Display Link.

I've completely reformatted the MAC, reinstalled Mojave 10.14.6 and reinstalled Office and a couple of other apps and this problem still happens.

I even have a video of this problem happening its that repetitive. Immediately prior to the CPU utilisation increase there is nothing visible in the activity monitor that would show why the increase is occurring. Similar, given I know exactly what time the issue is going to occur I know where in the logs to look and there appears to be nothing at all logged other than my bluetooth mouse.

I'm lost for idea's other than ensuring I disconnect the monitor prior to 1740!!! The only other option I can think of is returning to High Sierra to see if the problem remains. I don't see anyway of reverting back to other interim Mojave releases prior to 10.14.6.

Any suggestions ? I'd really like not to lose 30 minutes of my day while my MAC freaks out but I have run out of ideas.

Some more detail by using the log show command with debug. Seems that the Mojave kernel is starting some thing at 17.39.26 in the afternoons. There are people on the Displaylink forums that have noticed the issue but assumed its a Displaylink issue but its just more pronounced with DisplayLink because I think its trying to keep up with WindowServer.

Looking through the log show --debug --start at 1739 I repeatedly see this being logged. The time span between the messages is probably the CPU increase I'm assuming. This logging of flipping the the display from 2880x1800 to 2880 x1800 continues until whatever is causing it finishes at 1810 each day. 

I've no idea what is happening but the MAC gets so hot that its like a bar heater after that 30 minutes of running with Displaylink installed. 

I'm not sure what kicks this off I can not see anything in the logs. The only thing occurring prior to this is advertisements of Bluetooth wireless. 

So there is kernel logging about the Graphics Framebuffer that seems to range from 0.01 ms apart to 20-30ms apart. At 1810 this message goes away...... 

So this happens every single day. On the weekend I'll waste more time on Apple and do a completely fresh install of Mojave and see if with nothing else on the System that the kernel looses it at this time. Many hours invested in this which is tarnishing my thoughts of Apple after all these years.

2019-09-24 17:39:26.011562+1000 0x2e8   Default  0x0         71  0  diskarbitrationd: [com.apple.DiskArbitration.diskarbitrationd:default] <private>

2019-09-24 17:39:26.038305+1000 0x71e   Default  0x0         0   0  kernel: (AppleIntelKBLGraphicsFramebuffer) [IGFB][INFO ] [Flip_Transaction] FB0: Flipping display with wsaa 1 flipped from 2880 x 1800 -> 2880 x 1800 on 49000000 with 801 options at stride 11520

2019-09-24 17:39:26.038311+1000 0x71e   Default  0x0         0   0  kernel: (AppleIntelKBLGraphicsFramebuffer) [IGFB][INFO ] [Flip_Transaction] Pipe Gamma Enable

2019-09-24 17:39:26.038312+1000 0x71e   Default  0x0         0   0  kernel: (AppleIntelKBLGraphicsFramebuffer) [IGFB][INFO ] [Flip_Transaction] Disabling Render Compression

2019-09-24 17:39:26.084544+1000 0x71e   Default  0x0         0   0  kernel: (AppleIntelKBLGraphicsFramebuffer) [IGFB][INFO ] [Flip_Transaction] FB0: Flipping display with wsaa 1 flipped from 2880 x 1800 -> 2880 x 1800 on 49000000 with 1 options at stride 11520

2019-09-24 17:39:26.118642+1000 0x71e   Default  0x0         0   0  kernel: (AppleIntelKBLGraphicsFramebuffer) [IGFB][INFO ] [Flip_Transaction] FB0: Flipping display with wsaa 1 flipped from 2880 x 1800 -> 2880 x 1800 on 46600000 with 801 options at stride 11520

2019-09-24 17:39:26.118649+1000 0x71e   Default  0x0         0   0  kernel: (AppleIntelKBLGraphicsFramebuffer) [IGFB][INFO ] [Flip_Transaction] Pipe Gamma Enable

2019-09-24 17:39:26.216588+1000 0x71e   Default  0x0         0   0  kernel: (AppleIntelKBLGraphicsFramebuffer) [IGFB][INFO ] [Flip_Transaction] FB0: Flipping display with wsaa 1 flipped from 2880 x 1800 -> 2880 x 1800 on 46600000 with 1 options at stride 11520

2019-09-24 17:39:26.244896+1000 0x71e   Default  0x0         0   0  kernel: (AppleIntelKBLGraphicsFramebuffer) [IGFB][INFO ] [Flip_Transaction] FB0: Flipping display with wsaa 1 flipped from 2880 x 1800 -> 2880 x 1800 on 49000000 with 801 options at stride 11520

2019-09-24 17:39:26.244900+1000 0x71e   Default  0x0         0   0  kernel: (AppleIntelKBLGraphicsFramebuffer) [IGFB][INFO ] [Flip_Transaction] Pipe Gamma Enable

2019-09-24 17:39:26.351724+1000 0x71e   Default  0x0         0   0  kernel: (AppleIntelKBLGraphicsFramebuffer) [IGFB][INFO ] [Flip_Transaction] FB0: Flipping display with wsaa 1 flipped from 2880 x 1800 -> 2880 x 1800 on 49000000 with 1 options at stride 11520

2019-09-24 17:39:26.378806+1000 0x71e   Default  0x0         0   0  kernel: (AppleIntelKBLGraphicsFramebuffer) [IGFB][INFO ] [Flip_Transaction] FB0: Flipping display with wsaa 1 flipped from 2880 x 1800 -> 2880 x 1800 on 46600000 with 801 options at stride 11520

2019-09-24 17:39:26.378824+1000 0x71e   Default  0x0         0 

Absolutely nothin under google for that message of flipping the display. Does not leave much hope. Guess its back to High Sierra as the only other option by the looks. Pretty sad but there is no way of stepping backwards fro 10.14.6 to anything earlier and I guess there is not enough noise for Apple to care about fixing this if its just in 14.6.

Discussed with Apple Support yesterday as to what the OS is doing that sends the kernel into a state of attempting to change/alter the resolution on the display so often and for 30 minutes. After some discussion it was suggested to disable Night Shift. I did this and yesterday afternoon was the first day in a long time where the WindowServer process did not go high CPU with an Apple external Monitor connected to it. I'm hoping that this holds for the next couple of days. If so I'll update the ticket with this apparently being a bug with 10.14.6 18G95 with the hope that some thing can be done in Catalina to fix the issue.

With NightShift turned off there is no problems with the WindowsServer process. The MAC has worked for 2 days. Today I decided to enable NightShift just after the sun goes down. Immediately on enablement the WindowServer Process goes to 40%. I then disable NighShift and theWindowServer process returns to 3%. I repeat this process 3 times and its the same every time.

I then disconnect the external displays and repeat just with the MAC screen and no issues at all with the Window Server process.

Reattach the external Displays and repeat and the WindowServer process goes high each time.

This is on a 2017 MAC with 18G95 on a fresh install of Mojave.

Looking forward to a fix obviously in Catalina.

Thanks. After scrapping the entire MAC thinking it had some malware or virus etc and the problem persisting I ended up with Apple support to identify that it was Night Shift. Pity, really great feature thats now broken if your using your Mac in an Enterprise environment. Just home hacking with no external display is not an issue. Hopefully in one of the Catalina releases it may get fixed. I'm now just not holding my breadth that it will be any time soon.

Thanks for the reply, appreciate it.

Well thought I would see if apples Mojave SU2 fixed anything. Guess I was hoping too much. Still same outcome. Turn NightShift on and 40% WindowServer CPU load with an external monitor. Turn it off 3% load. Turn it on 40% load....you get the idea ;(.