Max scheduler pauses when holding the mouse on the window title bar (Windows 11 25H2)
### Environment
* Windows 11 Home 25H2
* Ableton Live 12.4.3
* Max 9.1.4 (bundled with Ableton Live)
### Description
I have found what appears to be a scheduler-related issue.
A very simple Max patch stops running when I press and hold the mouse button on the title bar of the Max window (or a subpatcher window).
The problem occurs both in Max for Live and when opening the patch as a .maxpat using the bundled Max.
### Minimal patch
```
[toggle]
|
[metro 100]
|
[counter]
|
[number]
```
### Steps to reproduce
1. Open the patch.
2. Turn the metro on.
3. Press and hold the left mouse button on the window title bar.
4. Do not move the window.
### Expected behavior
The scheduler should continue to run normally while the mouse button is held.
### Actual behavior
* The metro stops.
* counter stops incrementing.
* JavaScript Task objects also stop.
* post() output stops.
* Audio generation driven by the scheduler also stops.
When the mouse button is released, execution resumes.
### Additional observations
If I immediately drag the window after pressing the title bar, the problem does *not** occur.
* If I resize the window, the scheduler does not stop completely, but timing becomes irregular.
* No loadbang is triggered.
* live.thisdevice does not output a new bang.
* No messages appear in the Max Console.
* The problem occurs with both metro and JavaScript Task, so it does not appear to be related to JavaScript.
* Overdrive on/off makes no difference.
* "Prioritize Scheduler Activity Over CPU" on/off makes no difference.
Because the issue is reproducible with a minimal patch and without any external objects, I suspect it may be related to the interaction between Max's scheduler and Windows window-message handling on Windows 11 25H2.
Here is the simplest example I could come up with.
I create a js object that simply forwards whatever it receives:
inlets = 1;
outlets = 1;
function bang()
{
outlet(0, "bang");
}Then I create the following patch:
[toggle]
|
[metro 500]
|
[js empty.js]
|
[60]
|
[makenote 100 200]
| |
[noteout]When I run this patch inside Max, clicking and holding the window title bar only makes the playback slightly irregular.
However, when I run exactly the same patch in Max for Live, playback stops completely until I release the mouse button.
The reason I need to click the title bar is simply to move the device window or to open a subpatcher.