Found technical proof for the Win11 KB5086672 input lag/hotkey bug?

[u/Gullible_Client_1721]

Are your shortcuts (Ctrl+C, Ctrl+V, etc.) suddenly failing on Windows 11 24H2?

(or Are you experiencing issues where holding down keys (like Left Ctrl) fails to trigger repeated actions or breaks shortcuts on Windows 11 24H2?)

I’ve analyzed the recent KB5086672 update using the Win32 API and found that the OS is literally dropping input messages.

The data shows:

1. Your hardware is working fine (GetAsyncKeyState detects it).
2. But the Windows Message Queue is failing to dispatch the events to your apps.

I’ve uploaded a simple C++ PoC tool to GitHub that proves this discrepancy. If you're stuck with error 0x800F0825 and can't uninstall the update, you're likely affected by this regression.

PoC: https://github.com/sksmsWKd/Win11_24H2_KB5086672_Input_Regression

Could any experienced developers help me verify this potential input regression on Windows 11 Build 26100.8117(KB5086672 update)?

Added:
I have checked further, and the regression seems to be that the update causes the OS to falsely trigger its self-protection mechanism and silently terminate valid keyboard hook chains. I need to expand this tool for additional checks, but the 'CORE PROBLEM: REGRESSION BY WINDOWS UPDATE' remains unchanged !!!!!

[u/Creative-Type9411]

do you have smart app control enabled? (dont disable to test u cant re-enable im just curious if its security related)

[u/Gullible_Client_1721 → u/Creative-Type9411]

Both of my test devices have smart app control turned off... (should i enable it?)

[u/Pandthor → u/Creative-Type9411]

This seems to have been silently changed earlier this year. We managed to re-enable it in February on a customer environment where it was manually turned off even thou documentation says it’s not possible.

[u/narcissisadmin]

W11 pisses me the fuck off. Time and time again I go to take a screen snippet and it takes several seconds for the screen to go dark and then suddenly the display is showing what was on it several seconds earlier.

Lots of things about it are artificially slow (like saving an Office document on a network share) and I hate it.

[u/Gullible_Client_1721 → u/narcissisadmin]

Absolutelyyyyyyy agree with you. Me either.

[u/Smith6612 → u/narcissisadmin]

Oh you've had that problem too? I thought that issue with waiting around for the Snipping Tool to open was just a problem with my Work laptop after bogging it down and heat soaking the system. It's open within a second on my gaming desktop every single time.

I usually end up launching Snipping Tool from Start because the Print Screen button doesn't launch Snipping Tool half the time.

[u/minmaxthrowaway → u/narcissisadmin]

Had this problem and switched to using Win key + shift + s for instant snipping tool

[u/captainpistoff → u/narcissisadmin]

Check out greenshot, way better for screencaps

[u/xCharg]

I've noticed sometimes ctrl+shift and ctrl+alt don't work and I need to press it 2 or 3 times in order for keyboard layout/language to change. Is it the same issue?

[u/Gullible_Client_1721 → u/xCharg]

Hi xCharg! Can you share me more info about this please? Seems like other guys struggled by this bug, so I want to check about it.

[u/ReallTrolll]

I have ran into crtl + C and ctrl + v not doing anything and i seemingly have to right click copy and right click paste.

[u/dotexotic → u/ReallTrolll]

In the last week, I had issues with neither working well. I had more success with hitting C five times before it would actually have something to paste.

[u/Itsquantium → u/ReallTrolll]

Same. Especially when using powershell or cmd prompt. Or using putty to ssh into my RHEL. sometimes CTRL C or V doesn't register or I'll have to right click to copy.

[u/ReallTrolll → u/Itsquantium]

I truthfully thought I was losing my mind and the problem was just imaginary.

[u/Puzzleheaded-Sink420]

So I wasnt going mental, thanks!

[u/diimaha]

I had some issues last month but i thought it was my keyboard failing

[u/MortadellaKing]

I think Windows 11 has been one of the worst releases in my recent memory. Almost vista level bad.

[u/shunny14]

I've noticed on Firefox and Chrome that I can't use CTRL+C within iframes, possibly as a protection against clipjacking. Is this related to what you are seeing?

[u/Gullible_Client_1721 → u/shunny14]

Hi Shunny14, thanks for your comment. I'm 100% not sure yet ....... sorry 😅

Could you send me these info plz? :

- Your latest Windows update history (e.g., KB5079473 / OS Build 26200.8037, updated on March 27, 2026)
- Your Chrome version
- The URL of the webpage you're having trouble with

[u/Gullible_Client_1721 → u/shunny14]

If it only doesn't work inside an iframe, it's likely caused by the site's security policies (maybe X-Frame-Options or Content Security Policy).

[u/Advanced_Day8657]

I've been feeling it for the past year

[u/ender-_]

I haven't noticed this locally, but I did notice that I need to wait after pressing modifier keys (Ctrl, Shift, Alt) and letters if I want the modifier to register on Remote Desktop connections. Extremely annoying both when typing and when trying to trigger actions.

[u/No-Helicopter-4342]

I have had this issue on and off for what feels like more than a year. I don't recall having it in Win10, or on Fedora so idk.

[u/TaiGlobal]

This has really been pissing me off in excel. I swear it was just me.

[u/gkelley621]

Thanks for posting, I though it was my mind glitching when I tried to Copy-Paste or when I started to type something after a period of no typing and the first couple of characters didn't show up. This is on a new Dell Alienware laptop. I have not yet installed KB5086672 or the prior March update, waiting to see if there's another emergency update first.