Windows 10 Start Menu renders with sharp corners and wrong accent color on 1st launch, fixes on 2nd launch

Before reporting your issue

• I have confirmed that this issue does not happen when ExplorerPatcher is not installed
• I do not have "register as shell extension" enabled
• I have tried my best to check existing issues

Repro ExplorerPatcher versions

26100.8457.70.3

Repro Windows Versions

Windows 10 Pro 22h2 Build 19045.6093 x64

Third-party tweak software installed

TaskbarX

Describe the bug

When opening the Windows 10 Start menu for the first time after booting or restarting explorer.exe, it renders incorrectly with sharp corners and a darker/wrong accent color (as shown in the 1st attached screenshot).

However, after closing it and opening it for the second time, the rendering fixes itself: rounded corners and the correct light theme accent color apply properly (as shown in the 2nd attached screenshot).

Steps to Reproduce

1. Configure ExplorerPatcher to use the Windows 10 Start menu style with rounded corners enabled.
2. Restart explorer.exe or reboot the PC.
3. Open the Start menu for the 1st time -> It renders with sharp corners and incorrect background styling/accent color.
4. Close it and open it for the 2nd time -> It renders properly with rounded corners and correct accent colors.

Expected behavior

The Start menu should render with rounded corners and the correct accent color/transparency immediately on the first open, without needing to open and close it twice.

Additional Context

• Windows Version: Windows 10

Expected outcome

The Start menu should immediately open with rounded corners and the correct light theme accent color on the very first attempt.

Actual outcome

On the 1st attempt, the Start menu opens with sharp corners and a darker/incorrect accent color. It only renders with rounded corners and proper colors starting from the 2nd attempt.

Additional info

No response

Crash Dumps

No response

Media

first time after booting or restarting

second time, the rendering fixes itself

Start by reproducing the first-launch and second-launch difference after restarting explorer.exe on the reported Windows 10 version, with rounded corners enabled. Trace ExplorerPatcher's Windows 10 Start menu initialization and styling path to determine why corner and accent settings are applied only after the first open. Done means the first opening matches the later opening without requiring a second launch.