John SiracusaMar 31, 2023

I've been tracking this one down for a few days. Ever since I updated to macOS 13.3, window dragging sometimes looks like this.

It happens with any window in any app. It stops when I hide some(?) other windows. Not sure why and which windows, but I'm working on it…

Show threadJohn SiracusaApr 24, 2023

Here's a better screen recording of the laggy-window-dragging bug I described earlier (currently filed with Apple as FB12122106)

https://youtu.be/h0bKmcsMFvw

FB12122106 Demonstration

YouTube
Show threadSteve Troughton-SmithApr 24, 2023
@siracusa that jittering tells me some other process is trying to update the window position as you're dragging it
Show threadJohn SiracusaApr 24, 2023
@stroughtonsmith I’ve been assuming it’s the snap-to-window-edge feature that was added to macOS several years ago, but somehow going haywire since 13.3 was released.
Show threadJohn SiracusaApr 24, 2023
@stroughtonsmith Notice how it chills out once the number of visible windows is reduced. It’s like a bad algorithm for window placement that goes off a cliff once N gets too big.
Show threadGeorge Nachman
@siracusa does it happen with your own app’s window? If so set a breakpoint in windowDidMove and you can tell from the call stack if accessibility caused it. That would implicate a third party app.
Apr 25, 2023 at 3:53pmWeb