[bug] anomali found when fullscreen in macos

[shiqocred]

Describe the bug

When I click fullscreen, I see a strange glitch at the top of the window. Is there still no solution for keeping the window decoration disabled when fullscreen is true?

tauri.conf.json

"app": {
    "windows": [
      {
        "title": "tauri-test",
        "width": 800,
        "height": 600,
        "decorations": false,
        "transparent": true,
        "hiddenTitle": true,
        "titleBarStyle": "Overlay"
      }
    ],
    "macOSPrivateApi": true,
    "security": {
      "csp": null
    }
  },

lib.rs

use tauri::Manager;
use window_vibrancy::{apply_blur, apply_vibrancy, NSVisualEffectMaterial};

#[cfg_attr(mobile, tauri::mobile_entry_point)]
pub fn run() {
    tauri::Builder::default()
        .setup(|app| {
            let window = app.get_webview_window("main").unwrap();
            if cfg!(debug_assertions) {
                app.handle().plugin(
                    tauri_plugin_log::Builder::default()
                        .level(log::LevelFilter::Info)
                        .build(),
                )?;
            }
            match std::env::consts::OS {
                "macos" => {
                    apply_vibrancy(&window, NSVisualEffectMaterial::HudWindow, None, Some(14.0))
                        .expect(
                            "Unsupported platform! 'apply_vibrancy' is only supported on macOS",
                        );
                }
                "windows" => {
                    apply_blur(&window, Some((18, 18, 18, 125)))
                        .expect("Unsupported platform! 'apply_blur' is only supported on Windows");
                }
                _ => {}
            }
            Ok(())
        })
        .run(tauri::generate_context!())
        .expect("error while running tauri application");
}

https://github.com/user-attachments/assets/742993e1-3567-4508-9150-b411f192ea0c

Reproduction

No response

Expected behavior

No response

Full tauri info output

nothing

Stack trace

Additional context

system: macOS Tahoe version: 26.1

[dependencies]
serde_json = "1.0"
serde = { version = "1.0", features = ["derive"] }
log = "0.4"
tauri = { version = "2.9.2", features = ["macos-private-api"] }
tauri-plugin-log = "2"
window-vibrancy = "0.7.1"

"@tauri-apps/api": "^2.9.0",
"@tauri-apps/cli": "^2.9.4",

[FabianLars]

same behavior without window-vibrancy?

[shiqocred]

Yes, I’ve tried several scenarios. The main issue seems to be the ‘decoration’. Even when decoration is set to false, it becomes true when entering fullscreen, and it might already be true during the fullscreen animation. When I use decoration enabled, everything works normally and I don’t see any anomalies

[Tunglies]

Me too. I replace to max screen instead of full screen. :)

❯ cargo tauri info

[✔] Environment
    - OS: Mac OS 26.1.0 arm64 (X64)
    ✔ Xcode Command Line Tools: installed
    ✔ Xcode: 26.1.1
    ✔ rustc: 1.91.0 (f8297e351 2025-10-28)
    ✔ cargo: 1.91.0 (ea2d97820 2025-10-10)
    ✔ rustup: 1.28.2 (e4f3ad6f8 2025-04-28)
    ✔ Rust toolchain: stable-aarch64-apple-darwin (overridden by environment variable RUSTUP_TOOLCHAIN)
    - node: 25.2.1
    - pnpm: 10.22.0
    - yarn: 1.22.22
    - npm: 11.6.2
    - bun: 1.2.21
    - deno: deno 2.5.6

[-] Packages
    - tauri 🦀: 2.9.4
    - tauri-build 🦀: 2.5.3
    - wry 🦀: 0.53.5
    - tao 🦀: 0.34.5
    - tauri-cli 🦀: 2.9.5

[-] Plugins
    - tauri-plugin-window-state 🦀: 2.4.1
    - tauri-plugin-shell 🦀: 2.3.3
    - tauri-plugin-fs 🦀: 2.4.4
    - tauri-plugin-clipboard-manager 🦀: 2.3.2
    - tauri-plugin-global-shortcut 🦀: 2.3.1
    - tauri-plugin-process 🦀: 2.3.1
    - tauri-plugin-updater 🦀: 2.9.0
    - tauri-plugin-http 🦀: 2.5.4
    - tauri-plugin-dialog 🦀: 2.4.2
    - tauri-plugin-notification 🦀: 2.3.3
    - tauri-plugin-autostart 🦀: 2.5.1
    - tauri-plugin-deep-link 🦀: 2.4.5

[-] App
    - build-type: bundle
    - CSP: unset
    - frontendDist: ../dist
    - devUrl: http://localhost:3000/