WPF window stops rendering when using a BitmapCache inside while another window is invisible

* .NET Core Version: 3.0
* Windows version: Windows 7/8/8.1/10 (Any Windows 10 versions including 10.0.18362.329)
* Does the bug reproduce also in WPF for .NET Framework 4.8?: Yes

**Problem description:**
If a `Window` contains any `UIElement` with a `BitmapCache` and another window is hidden, the first `Window` will stop rendering in two different situations:
1. Lock and unlock the screen
1. Wait for a while (e.g. 10~30min)

**Actual behavior:**

See this animation below and you'll see that the window stops rendering after a locking and unlocking screen.


**Expected behavior:**

The window should keep rendering.

**Minimal repro:**

1. Make a window shown with a BitmapCache inside
1. Show and hide another window
1. Lock and unlock the screen
1. Resize the first window to view the behavior

See this minimal reproduction repository below:

- [wpf-issues/BitmapCache at master · dotnet-campus/wpf-issues](https://github.com/dotnet-campus/wpf-issues/tree/master/BitmapCache)