Any in-app blur/acrylic texture appears broken

[marticliment]

Describe the bug

Any blur/acrylic texture (scrollbars, comboboxes, etc.) shown on the app does not show any transparency. It instead shows an opaque grey blur.

Moreover, a list of errors get printed on console. This is only a small part of it.

BVI-FullRender

BVI-CouldNotFindCachedBlur

BVI-CachedNewBlur
(1.00, 0.00, 0.00, 0.00), (0.00, 1.00, 0.00, 0.00), (0.00, 0.00, 1.00, 0.00), (10.00, 2.00, 32.00, 1.00)
0.00, 0.00, 200.00, 417.00 (200.00 x 417.00)
rcBackdropLocal=[0.00, 0.00, 200.00, 417.00 (200.00 x 417.00)], worldTransform=[(1.00, 0.00, 0.00, 0.00), (0.00, 1.00, 0.00, 0.00), (0.00, 0.00, 1.00, 0.00), (10.00, 2.00, 32.00, 1.00)]
BVI-Validate-DidNotInvalidateCache

BVI-RealizationIsDirty-NotUpdated
(1.00, 0.00, 0.00, 0.00), (0.00, 1.00, 0.00, 0.00), (0.00, 0.00, 1.00, 0.00), (10.00, 2.00, 32.00, 1.00)
0.00, 0.00, 200.00, 417.00 (200.00 x 417.00)
rcBackdropLocal=[0.00, 0.00, 200.00, 417.00 (200.00 x 417.00)], worldTransform=[(1.00, 0.00, 0.00, 0.00), (0.00, 1.00, 0.00, 0.00), (0.00, 0.00, 1.00, 0.00), (10.00, 2.00, 32.00, 1.00)]
BVI-Validate-InvalidatedCache

BVI-FullRender

BVI-CouldNotFindCachedBlur

BVI-CachedNewBlur
(1.00, 0.00, 0.00, 0.00), (0.00, 1.00, 0.00, 0.00), (0.00, 0.00, 1.00, 0.00), (10.00, 2.00, 32.00, 1.00)
0.00, 0.00, 200.00, 417.00 (200.00 x 417.00)
rcBackdropLocal=[0.00, 0.00, 200.00, 417.00 (200.00 x 417.00)], worldTransform=[(1.00, 0.00, 0.00, 0.00), (0.00, 1.00, 0.00, 0.00), (0.00, 0.00, 1.00, 0.00), (10.00, 2.00, 32.00, 1.00)]
BVI-Validate-DidNotInvalidateCache
(1.00, 0.00, 0.00, 0.00), (0.00, 1.00, 0.00, 0.00), (0.00, 0.00, 1.00, 0.00), (10.00, 2.00, 32.00, 1.00)
0.00, 0.00, 200.00, 417.00 (200.00 x 417.00)
rcBackdropLocal=[0.00, 0.00, 200.00, 417.00 (200.00 x 417.00)], worldTransform=[(1.00, 0.00, 0.00, 0.00), (0.00, 1.00, 0.00, 0.00), (0.00, 0.00, 1.00, 0.00), (10.00, 2.00, 32.00, 1.00)]
BVI-Validate-DidNotInvalidateCache
(1.00, 0.00, 0.00, 0.00), (0.00, 1.00, 0.00, 0.00), (0.00, 0.00, 1.00, 0.00), (10.00, 2.00, 32.00, 1.00)
0.00, 0.00, 200.00, 417.00 (200.00 x 417.00)
rcBackdropLocal=[0.00, 0.00, 200.00, 417.00 (200.00 x 417.00)], worldTransform=[(1.00, 0.00, 0.00, 0.00), (0.00, 1.00, 0.00, 0.00), (0.00, 0.00, 1.00, 0.00), (10.00, 2.00, 32.00, 1.00)]
BVI-Validate-DidNotInvalidateCache

Steps to reproduce the bug

Create a Window that hosts a control such as ComboBox.

Tested with:

• Windows 11 Insider Beta Channel (22635.3061)
• App Sdk 1.4.XXX (various versions to make surt)
• Visual Studio 2022 preview

The bug persisted even when:

• Mica was disabled and default background was set
• Regular acrylic backdrop was set. (DesktopAcrylicBackdrop renders fine, controls still do not show properly)
• Other libraries such as Pythonnet were not imported
• The project was ran in both "Exe" and "WinExe" output types.
• The project was executed from a release build
• The project was debugged from a debug build

Expected behavior

Comboboxes and other widgets render properly and no messages appear on the console.

Screenshots

How it is rendering

How it should render

NuGet package version

Windows App SDK 1.4.3: 1.4.231115000

Packaging type

Unpackaged

Windows version

Insider Build (xxxxx)

IDE

Visual Studio 2022-preview

Additional context

This issue appears to be happening also to other App Sdk apps such as the WinUI 3 Gallery, also using App SDK 1.4:

(the WinUI 2 Gallery app renders comboboxes as expected)

[lolametro]

For completeness sake, this seems to be the case for at least:

• Flyout
• DatePicker
• TimePicker
• ToolTip
• ComboBox (Acrylic Brush doesn't work in combobox #9523)
• TeachingTip (ShouldConstrainToRootBounds = False disables backdrop #8657)

In WinUI 2, it's Acrylic blurred by default, in WinUI 3 not.
Would be nice if they are fixed in a batch.