Brightness and Volume Cause System Slowdown

Describe the bug
I have the keyboard set to increase or decrease brightness with (r)Option+/ and (r)Option+.
I have the keyboard set to increase or decrease volume with (r)Command+/ and (r)Command+.
But when I use these commands, my Mac slows and stutters, and a noticeable pause happens before the HUD shows volume or brightness changing. Whatever I happen to be doing (usually Youtube on Safari) also slows and stutters at the same time. But this also happens when I'm just using email or surfing the web, not only when I'm watching a video.
This does not happen when I use the volume or brightness slider on the Touch Bar. In that case, the HUD comes up smoothly with no delay and no stuttering of system.

Affected input device (e.g. MacBook Trackpad, Magic Mouse/Trackpad, Touch Bar, etc.):
The MacBook keyboard itself.

If applicable, add screenshots to help explain your problem. (You can just paste or drag them here)

Device information:

  • Type of Mac: MacBook Pro 15 inch (2017)
  • macOS version: Mac OS Big Sur 11.5.1
  • BetterTouchTool version: 3.570

Can confirm, same issues for me.

  • MacBook Pro (15-inch, 2018)
  • Mac os 11.5 (20G71)
  • BetterTouchTool version: 3.570

This seems to be a macOS bug in 11.5.x I'll look for a workaround.

Can you confirm that this even happens without BTT, e.g. with the system Touch Bar when extending the control strip and pressing the volume up / down buttons?

Or if you have a normal keyboard - is pressing the volume buttons also slow for you?

Apparently this is a known Apple bug in macOS 11.5, restarting macOS fixes the issue temporarily but I don't know for how long.

Unfortunately I think this can only be fixed by Apple.


Thanks for your reply.

This only happens when I use the BTT keyboard shortcuts that I programmed.

The Touch Bar control strip volume/brightness slider does not slow down the system at all, it seems quite smooth as usual (brightness and sound HUD come up right away, and the adjustments happen in real time with no stuttering or delay).

the sliders work fine, but did you also try the buttons in the expanded control strip? I have found many reports on the Apple forums for the issue with the standard volume/brightnes keyboard keys, which is why I believe it’s causing the issues in BTT as well. (because BTT emulates these standards buttons)

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Ah, you are right! The Touch Bar button volume/brightness adjusters do cause the system to stutter. I hope Apple fixes it in the next OS release.

I'm pretty sure they will because many people encounter this, I have just created another bug report for it in the developer portal.

There are various issues with the 11.5.x release, so I believe there will be another update soon. Maybe I can create a temporary workaround that directly modifies the volume, I'll check tomorrow.


Sure, thank you for your effort.

I have a bit different issue, but it might be related.

I have two, three Touch Bar gestures to change volume and brightness. After the restart works flawlessly, but after 1-2 days without restart it keeps stuttering and after 4+ days it becomes unusable. The only fix I found restart the Mac.

if the gestures are triggering the volume up/down actions in BTT, it’s the same issue.

I had the same problem and resetting SMC on my MBP 16 (L-ctrl+L-Option+R-Shift+ Power) solved the problem for me.
Hope this helps :slight_smile:
EDITED: Oops, it's doing it again after the system being asleep... Relaunching the Finder gets rid of the problem. I really don't know if the problem is MacOs or BTT...


Completely unusable for me.

Anyone know if apple has acknowledged this? Volume and brightness practically inoperable from keyboard for me.

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Same happening to me. I first noticed it a few weeks ago. Apple's touch bar works fine but BTT one has a response time of like 3-5 seconds, rendering it not very useful.

I was relieved to find this discussion yesterday and learn that I was not the only one with the problem. I have now updated my MacBook Pro to MacOS 11.5.2, just released today. From what I can tell so far, the problem is fixed.

Yes, seems to be fixed with macOS 11.5.2.

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Yes, I think it is fixed. Thanks for putting in the bug fix request, Andreas.