Steam Overlay doesn't work when launching games with cores via CLI

Description

When launching games directly via command line (retroarch.exe -L ) with RetroArch for Steam the overlay won't launch.
I asked on Discord and was told to try hooking the overlay manually via GameOverlayUI.exe -pid -manuallyclearframes 0 and that didn't work either. Didn't get an error but the overlay also didn't work.
When launching RetroArch for Steam directly from Steam without command line arguments the overlay works fine.

Expected behavior

Overlay should work.

Actual behavior

The hotkey for the overlay doesn't do anything and when RetroArch is launched the Notifications are also not shown. The game itself works fine.

Steps to reproduce the bug

1. Launch Steam
2. Launch Retroarch via CLI e.g. \steamapps\common\RetroArch\retroarch.exe -L "<path+core.dll>" "path+rom"
3. Try to bring up Overlay

Bisect Results

I've only recently switched from standalone to the Steam version and I've just been testing it for a couple of days. I don't think this works (yet)?

Version/Commit

You can find this information under Information/System Information

• RetroArch: Test with latest stable & nightly (Jul 10 2022)

Environment information

• OS: Windows 10
• Compiler: -

Start by tracing how the Windows CLI invocation differs from launching RetroArch for Steam directly, using the command and Steam overlay behavior described in the issue. Reproduce with the provided -L core and ROM arguments, then verify that the overlay hotkey and notifications work while the game remains functional.