Weird Firefox tab background on startup

[Nikkolix]

When I start Firefox 133 the top background, the top Background has this weird background:

After resizing or minimizing the window, it looks like it is supposed to:

How can I get the result on startup without window resizing?

toolkit.legacyUserProfileCustomizations.stylesheets true
svg.context-properties.content.enabled true
DarkTheme.Tabs.Borders.Saturation.High.Enabled true
userChrome.DarkTheme.Tabs.Borders.Saturation.Low.Enabled true
userChrome.DarkTheme.Tabs.Borders.Saturation.Medium.Enabled true
userChrome.DarkTheme.Tabs.Borders.Saturation.VeryHigh.Enabled true
userChrome.DarkTheme.Tabs.Shadows.Saturation.High.Enabled true
userChrome.DarkTheme.Tabs.Shadows.Saturation.Low.Enabled true
userChrome.DarkTheme.Tabs.Shadows.Saturation.Medium.Enabled true
userChrome.DarkTheme.Tabs.Shadows.Saturation.VeryHigh.Enabled true
userChrome.DragSpace.Left.Disabled true
userChrome.DragSpace.Right.Disabled true
userChrome.DragSpace.Top.Fullscreen.Enabled true
userChrome.DragSpace.Top.Maximized.Enabled true
userChrome.DragSpace.Top.Windowed.Enabled true
userChrome.Menu.Icons.Regular.Enabled true
userChrome.Menu.Size.Compact.Enabled true
userChrome.OneLine.NavBarFirst.Enabled false
userChrome.OneLine.TabBarFirst.Enabled false
userChrome.Style.ThirdParty.Enabled true
userChrome.TabSeparators.Saturation.Low.Enabled true
userChrome.Tabs.Option5.Enabled true
userChrome.Tabs.Pinned.Width.LowOffset.Enabled true
userChrome.Tabs.SelectedTabIndicator.Enabled true
userChrome.Toolbar.Transparency.High.Enabled true
userChrome.Toolbar.Transparency.Low.Enabled true
userChrome.Toolbar.Transparency.Medium.Enabled true
userChrome.Toolbar.Transparency.VeryHigh.Enabled true
widget.windows.mica true
tyle.Menu-Icons-Regular true
Style.New-Tab-Button-Like-Pinned-Tab true
Style.Toolbar-Transparency-High true
Style.WaveFox true
Style.Win11-Mica-Acrylic true

[QNetITQ]

This is still an experimental feature. We'll have to wait for fixes.

https://bugzilla.mozilla.org/show_bug.cgi?id=1934143

[GammaBoost]

Am having the same issues.

Before resizing the window:

With DWMBlurGlass:

Without DWMBlurGlass:

After resizing the window:

With DWMBlurGlass:

Without DWMBlurGlass:

Currently using Firefox 133.0.3 on Windows 11 23H2.

toolkit.legacyUserProfileCustomizations.stylesheets true
userChrome.DragSpace.Left.Disabled true
userChrome.Tabs.Option8.Enabled true
userChrome.Toolbar.Transparency.High.Enabled true
userChrome.Windows.Transparency.Enabled true
browser.tabs.allow_transparent_browser true
widget.windows.mica false

Edit: It seems that sometimes (not always) I don't get the weirdly overlayed loading effects, but the colours are still wrong until I resize it: