macOS stutters every 2 seconds when an external monitor is plugged in

[petterihiisila]

I’ve bought a new Macbook Pro 16”. There is stuttering right after I have my external monitor plugged in. Stuttering is observed on both displays (on the internal Retina and the external LG display) while having connected the external LG display. Stuttering stops immediately right after ejecting the LG display.

I once had this same problem with some version of BetterTouchTool running. I made a shortcut key to restart BetterTouchTool itself, that made the stuttering go away. And a later version then got rid of the issue. Boy, it was difficult to diagnose at the time.

Some people still have that issue with newer versions. https://community.folivora.ai/t/stuttery-and-laggy-window-movement-when-using-btt/15941

I don't want to point any shame towards BTT, it's an awesome tool I use every minute, but if you have it running, try turning it off and see if it makes a difference. Just a hip shot idea.

 

[soulreaver99]

This is also happening on my M1 MacBook Air on both Apple's USB C Display, Anker and Aukey as well. Kind of frustrating!

 

[MacGizmo]

So it's a half-year later... other "issues" have come to light. Has anyone with this issue tried using a different/new cable to connect external LCD to the Mac? It doesn't appear to matter if it's USBC to USBC, or HDMI to USBC, Display Port to USBC, etc.

 

[soulreaver99]

So it's a half-year later... other "issues" have come to light. Has anyone with this issue tried using a different/new cable to connect external LCD to the Mac? It doesn't appear to matter if it's USBC to USBC, or HDMI to USBC, Display Port to USBC, etc.

what sort of fixed it for me was using a different thunderbolt port

what completely fixes it is reducing the refresh rate from 144hz down to 60hz which is a total drag especially coming from a higher rate!

this is definitely a software issue because i have no problems on my PC connected through either HDMI or DP.

 

[goodwilldrums]

It is absolutely an HDCP issue! I first noticed this problem while at work, a 2019 MBP 16" plugged into a production switcher for graphics, I would get this occasional lag on both displays. This is how I found this forum. I didn't, however, have this problem at home while plugging straight into an external monitor using the same usb-c hub I have at work.

Looks like a few on here have been able to solve this issue by upgrading the firmware on whatever external display they are using. If you tried that, or there isn't one available, I would try this because it's what solved it for me:

Being in the live production business I have over the years encountered HDCP issues with laptops not being able to properly connect to video switchers. So a work around is to use a little 1x2 HDMI DA that strips the HDCP from the cables (https://www.amazon.com/gp/product/B0089DSLMY/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1). There are others out there that will do the same thing. I am going to buy a couple of those since it seems that particular one has been discontinued.
But going through that little DA definitely fixed the lagging!

 

[IceStormNG]

I have the same issue since 11.3. But not every time. Just every second day. When my mac wakes up from sleep (with external monitor connected) it does exactly that. You can find the HDCP stall events in the system log and my mouse lags every few seconds. Only solution: Reboot the mac. No matter how I (re)connect my display, it won't go away until I reboot the MacBook.

Apple Support: "Your monitor is not macOS compatible".

11.4 didn't fixed that and 11.5 also not. My first 5 machines (yes: five) where replaced because of that issue as they had this stutter on the iGPU.
This one has it with external monitors but only since Big Sur.

So Apple: When will the "most advanced operating system" finally work?

 

[cmh44115]

I just created an account to post on this forum because this issue was driving me crazy. I upgraded to new monitors and this started occuring on a single monitor.

Not sure on forum rules regarding Hackintosh, but i can edit this if required.
I use a Radeon RX 5700 XT as my discrete card, and run 3 screens.
Running Big Sur 11.5.2 (20G95).

I am using: 2 x Dell S2721QS and 1 x Dell 3222DGM and only experienced the issue on one of the Dell S2721QS when connected via HDMI. The other two displays use Displayport and experience no issues.

Strangely both the 2721QS displays (which are 4k) get detected as 1920x1080 displays and i have to swap to scaled to get them to work corrrectly (not sure if this is expected behaviour?). But the 3222DGM (which is 1440p) get's detected correctly (although not at 165hz but this can be swapped in display settings).

So I was having the issue with the one via HDMI and simply changing the HDMI connection to the other HDMI port fixed it instantly. Swapping back to the prior port does not return the issue so it definitely appears to be some kind of software issue. I also tried a different HDMI cable and had no issues at all.

I know none of this is super detailed, but hopefully it at least shows its unlikley to be a hardware issue either with the monitor, cable or graphics card/output port. Will update if i have any return of issues here.

 

[hoessb]

Hey,
I had the same issue for months now. No luck with any of the mentioned workarounds.
Just installed Monterey Beta and the issue is GONE! Good luck.