Renderer reloads Nuxt3 SPA after a few minutes of inactivity – state lost even with AutomaticTabDiscarding/Disabled

[NelCit]

Is there an existing issue for this?

• I have searched both open/closed issues, no issue already exists.

CefSharp Version

135.0.170

Operating System

Windows 11

Architecture

x64

.Net Version

8.0

Implementation

WinForms

Reproduction Steps

Create a minimal CefSharp 120.× WPF app

Serve a basic Vue 3 SPA either:

from file://…/dist/index.html, or

via http://localhost:5173 (Vite dev server).

Interact with the UI so the page holds some transient state (e.g., text in a form).

Leave the window untouched for ≈ 5–10 minutes (exact delay varies).

Click anywhere inside the web view (that trigger a changement of url),

What i actually tried :

settings.CefCommandLineArgs.Add("force-fieldtrials",
"AutomaticTabDiscarding/Disabled");

settings.CefCommandLineArgs.Add("allow-file-access-from-files", "1");
settings.CefCommandLineArgs.Add("enable-local-file-accesses", "1");
settings.CefCommandLineArgs.Add("disable-background-timer-throttling", "1");
settings.CefCommandLineArgs.Add("disable-backgrounding-occluded-windows", "1");
settings.CefCommandLineArgs.Add("disable-renderer-backgrounding", "1");
settings.CefCommandLineArgs.Add("disable-site-isolation-trials", "1");
settings.CefCommandLineArgs.Add("disable-ipc-flooding-protection", "1");

Expected behavior

Is there another Chromium switch (or CefSharp setting) that prevents the renderer from being suspended / discarded after idle time?

Could this be a new power-saving feature in Chromium > 119 that ignores AutomaticTabDiscarding/Disabled inside CEF?

Any recommended workaround to keep a SPA alive (ping, synthetic event, etc.) until a proper fix is found?

Actual behavior

The renderer goes blank for a moment, then the full page reloads; all JS state and DOM changes are lost.

Regression?

No response

Known Workarounds

No response

Does this problem also occur in the CEF Sample Application

Yes using WPF/OffScreen command line args

Other information

No response

[amaitland]

Could this be a new power-saving feature in Chromium > 119 that ignores AutomaticTabDiscarding/Disabled inside CEF?

Any recommended workaround to keep a SPA alive (ping, synthetic event, etc.) until a proper fix is found?

https://www.magpcss.org/ceforum/index.php?sid=c7c6b31fcc433f8b9c714f47bd666e88 would be the best place to ask.

[amaitland]

#4835 (comment)

You should also try switching to chrome styled window as a workaround