[BUG] UniGetUI may open three windows all only showing grey

### Please confirm these before moving forward

- [x] I have searched for my issue and have not found a work-in-progress/duplicate/resolved issue.
- [x] I have tested that this issue has not been fixed in the latest [(beta or stable) release](https://github.com/Devolutions/UniGetUI/releases/).
- [x] I have checked the [FAQ](https://github.com/Devolutions/UniGetUI#frequently-asked-questions) section for solutions.
- [x] This issue is about a bug (if it is not, please use the [correct template](https://github.com/Devolutions/UniGetUI/issues/new/choose)).

### UniGetUI Version

2026.2.5

### Windows version, edition, and architecture

Microsoft Windows [Version 10.0.17763.316]

### Describe your issue

UniGetUI may open opening three windows. Each of them only showing a grey background with "Default IME" on lest top. Closing all three windows closes UniGetUI. Normal display is not restorable minimizing, then restoring any or all of the three windows.
Starting UniGetUI again most of the time solves this problem.

### Steps to reproduce the issue

Install UniGetUI 2026.2.5, then minimize UniGetUI while started. Then right after minimizing restore UniGetUI Window.
The Taskbar changes showing three windows.

### UniGetUI Log

```text
No access to logs via UniGetUI.
```

### Package Managers Logs

```text
No access to logs via UniGetUI.
```

### Relevant information

_No response_

### Screenshots and videos

Start by reproducing the issue using the reported UniGetUI 2026.2.5 and Windows 10 steps: minimize the application and immediately restore it. No source files, tests, or entry points are identified in the report; done means the application no longer opens three grey windows after this sequence and the behavior is covered by a verified fix.

Written by the indexing model from the issue text.