No easing function required for SlideLockScreen IsVisible setter.
MODIFY
WalletWasabi.Gui/Controls/LockScreen/SlideLockScreen.xaml
WalletWasabi.Gui/Controls/LockScreen/SlideLockScreen.xaml
</Style>
<Style Selector="lockscreen|SlideLockScreen[IsLocked=true]">
<Style.Animations>
- <Animation FillMode="Both" Duration="0:0:1.5" Easing="QuarticEaseInOut">
+ <Animation FillMode="Both" Duration="0:0:1.5">
<KeyFrame Cue="0%">
<Setter Property="IsVisible" Value="True" />
</KeyFrame>
</Style>
<Style Selector="lockscreen|SlideLockScreen[IsLocked=false]">
<Style.Animations>
- <Animation FillMode="Both" Duration="0:0:1.5" Easing="QuarticEaseInOut">
+ <Animation FillMode="Both" Duration="0:0:1.5">
<KeyFrame Cue="99%">
<Setter Property="IsVisible" Value="True" />
</KeyFrame>

No easing function required for SlideLockScreen IsVisible setter.