[BUG] Claude Code desktop app (Windows/MSIX): stutter and brightness flashes with GPU rendering; smooth with --disable-gpu

Component: Claude Code desktop app (Claude Desktop), Windows, MSIX package

Problem

Heavy stutter and small brightness flashes while using the app. Everything else on the machine is fine.

Environment

• Claude Desktop 2.9939.4.0 (MSIX / Microsoft Store package)
• Windows 11 Pro 10.0.26200
• GPUs: NVIDIA GeForce RTX 5070 Ti (driver 32.0.16.1714, dated 2026-09-17) + AMD Radeon iGPU (driver 32.0.21045.5002)
• Two monitors: Samsung Odyssey G61SD (2560x1440) and G70NC (3840x2160)

Ruled out

• Refresh rate mismatch: same result with both monitors set to 120 Hz
• GPU selection: forced Claude.exe to "High performance" (RTX 5070 Ti) in Windows Graphics settings; the GPU process was confirmed to run on the NVIDIA adapter
• Windows VRR / windowed-game optimizations were already off
• Only Claude is affected; other windowed apps are fine

Workaround (confirmed)

Launching the packaged executable directly with --disable-gpu makes the app completely smooth:

& "C:\Program Files\WindowsApps\Claude_2.9939.4.0_x64__pzs8sxrjxfjjc\app\Claude.exe" --disable-gpu

This works despite MSIX, so the flag can be passed. There is still no in-app setting to disable hardware acceleration.

Suspicion (not verified)

GPU compositing/rendering issue, possibly related to the recent NVIDIA driver or the dual-GPU setup.

Related

Possibly the same subsystem as #26302 and #77857 (closed, auto-labeled invalid because the title did not mention Claude Code).

Request

Please add an in-app "Disable hardware acceleration" option, or investigate the GPU rendering path on Windows with dual-GPU setups.