[Bug] Millennium not starting correctly on startup.

[AsuToki360]

Before Reporting

• [X] I found no existing issues matching my bug
• [ ] My issue is not caused by the Millennium interface inside Steam (Themes, Plugins & Update Panel). If it is, make a issue report in this repo.
• [X] My issue is not caused by a theme

Describe the Bug

For some reason Millennium doesn't launch the way as it should. There's no options and the theme is only applied for some pages (like the Workshop or the Store) but not on the entire client.

When I close Steam entirely and open it again, it opens with my theme 100% applied and everything, strange...

Expected Behavior

Steam launcing correctly with my theme applied.

Steps To Reproduce

1. Boot my PC (or restart it)
2. Open Steam

Operating System

Windows

Anything else?

No response