BUG: The background is still black when backdrop type is mica alt on win 11 and flow launcher version 2.1.3

### Checks

- [x] I have checked that this issue has not already been reported.

- [x] I am using the latest version of Flow Launcher.

- [ ] I am using the prerelease version of Flow Launcher.

### Problem Description

i was making a theme of my own and when testing it out i found out that the blur effect i had added was not loading at all unless the backdrop type is acrylic, i tried a lot of things but the blur effect is not loading, although there are similar issues out there in this repo those are for version 2.1.2 and most of the solutions suggested there are just to update the app to 2.1.3 and as i am on 2.1.3 and I'm still having the same issue

issues i check before: #3434 and #4512

### To Reproduce

1. update to version 2.1.3
2. Use a background blur theme
3. Set backdrop to mica alt

### Screenshots

_No response_

### Flow Launcher Version

2.1.3

### Windows Build Number

[Version 10.0.26200.8973

### Error Log

No source files or tests are named. Reproduce on Windows 11 build 10.0.26200.8973 with Flow Launcher 2.1.3, a background-blur theme, and the mica alt backdrop, then compare it with acrylic; done means the configured blur effect renders with mica alt as well.

Written by the indexing model from the issue text.