MenuFlyoutSubItem can be laggy when opening on mouse over

[jeremy-visionaid]

Describe the bug

There can sometimes be a significant/noticeable delay when displaying a MenuFlyoutSubItem's MenuFlyoutItems

Steps to reproduce the bug

This is reprodicible in WinUI 3 Gallery:
"Menu & toolbars" -> "MenuFlyout"
Then click "File Options" and hover over "Send to"

Occassionaly this takes a few seconds to display the sub items (not every time, but maybe 1 in every 5)

Originally noticed it in a MAUI app, but it appears to affect all Win UI 3 applications

Expected behavior

Sub items should start animating into view immediately on mouse over

Screenshots

No response

NuGet package version

WinUI 3 - Windows App SDK 1.4.5: 1.4.240411001

Windows version

Windows 11 (22H2): Build 22621

Additional context

No response

[github-actions]

Hi I'm an AI powered bot that finds similar issues based off the issue title.

Please view the issues below to see if they solve your problem, and if the issue describes your problem please consider closing this one. Thank you!

Open similar issues:

• Can't add MenuFlyoutItem to MenuFlyoutSubItem at runtime (#7797), similarity score: 0.74
• MenuFlyout requires 'slow moving cursor' (so my Terminal Tabs are finicky) (#8921), similarity score: 0.71

Closed similar issues:

• MenuFlyout causes application crash (#8954), similarity score: 0.72

Note: You can give me feedback by thumbs upping or thumbs downing this comment.

[jeremy-visionaid]

#8921 looks pretty similar, but I can't judge if this is really a duplicate or not. This one doesn't appear to be affected by the cursor movement speed.

[kmgallahan]

Possibly same issue as #939 with diagnosis found here: #939 (comment)

[jeremy-visionaid]

@kmgallahan Oh yup, that's the one! I am running a high refresh rate screen... If I set it back down to 60 Hz then the problem goes away... Not the first time I've seen something like this with WinUI 3. I couldn't even target an app against it previously at all because of refresh rate related perf issues like #7290 / #6031 that made it unsuitable for displaying video etc.

Anyways, #939 is a proposal to change the behaviour on clicking the menu items, and this is explitly calling out the display refresh rate performance issue as a bug... Up to you if you want to close this as a dupe.

[kmgallahan]

@DmitriyKomin There are multiple issues related to this: #939 #8921 #9371, plus other elsewhere like microsoft/terminal#14756, & microsoft/terminal#15545

[bpulliam]

Resolving as a duplicate of #8921

[gegao18]

Update - we have two separate issues here. #939 and #8921 deal with a slight delay when expanding cascading menus with a click. This delay exists regardless of the device.

There is also a problem in the way that WinUI 3 handles its clock that causes major delays on variable refresh rate devices, which can cause multi-second delays in DispatcherTimers firing, which then affects things like menus which wait for those timers. I believe that's what this thread is hitting. We have a fix for this variable refresh rate problem coming in 1.5.2.

[fredemmott]

@gegao18 that’s great! Any chance of a backport to 1.4? I’m using v1.5 in my master branch, but 1.4 -> 1.5 is a too big of a change for me to put in the existing stable branch of my app