[Bug]: Halved framerate in-game after adding overlay, even when overlay not visible

[anslogen]

Bug Description

Hey there, was happy with how smooth this was to set up and integrate, but I'm noticing that the general framerate of the game is stuck around 30fps after adding the overlay, whether or not the overlay is open.

So far all I've done is a minimal integration with the basics, following the tutorial for electron overlay integration.

It initialises and operates just fine, but the FPS wavers around 25-35, even when the overlay isn't open. For context, I'm on a 75Hz monitor. The in-game FPS still reads 75, though it certainly looks and feels 30fps, and this is the value that the Steam performance overlay shows too.

I've tried disabling vsync and lowering the FPS in the addElectronSteamOverlay options, but they made no difference.

I'd be grateful if you know what might help - thanks!

Steps to Reproduce

Initialise Steam with init({appId: 480})
Initialise overlay with addElectronSteamOverlay(mainWindow)
Launch game with Steam open and observe ~30fps shown in the steam performance overlay

Expected Behavior

No impact on FPS with the overlay enabled, whether visible or not

Actual Behavior

Roughly halved FPS globally throughout the app, even in pause state or menus

Code Sample

steam.init({appId: APP_ID})

...

setInterval(() => { steam.runCallbacks(), 1000} )

...

if(steam.isOverlayAvailable()) {
  steam.addElectronSteamOverlay(mainWindow)
}

Affected API

Overlay API

Package Version

0.10.4

Operating System

Windows 11

Node.js Version

v24.13.1

Environment

Node.js (vanilla)

Error Logs

Checklist

• I have searched existing issues to ensure this bug hasn't been reported
• Steam client is running and I'm logged in
• I have run npm run verify-sdk and it passes

Additional Context

• Building a web app with electron-builder
• Overlay does work at normal FPS with steamworks.js, though this is non-viable due to a window duplication bug when alt-tabbing