Green block artifacts in exports when Intel hardware decoding is on (Core Ultra 7 270K Plus iGPU, Sony A7 IV 4K 50p H.264)

Issue: Green block artifacts appear on some clips in exports and in the Media Encoder output preview when Intel hardware-accelerated H.264/HEVC decoding is enabled. Turning off only Intel decoding, with Nvidia decoding and hardware encoding left on, fully fixes it. It still happens on the latest Intel graphics driver (32.0.101.9150).

Steps to Reproduce:

1. Preferences → Media: enable H.264/HEVC hardware accelerated decoding with both Intel and Nvidia checked, and enable hardware accelerated encoding.
2. Restart Premiere Pro.
3. Edit Sony A7 IV 4K 50p footage in a 1080×1920, 25 fps sequence.
4. Export from Premiere Pro or Media Encoder (tested with H.264, HEVC and Apple ProRes 422 HQ).

Expected Result: Clean output matching the source footage.

Actual Result: Green block artifacts on some clips (3 clips in my latest export), in both the exported file and the Media Encoder output preview. Task Manager shows the Intel iGPU at 100% at the start of the export before the NVIDIA GPU takes over, so the Intel decoder is in use when the corruption happens.

Screen Recording: [Attach recording or screenshot of the green frames]

Premiere Version: Reproduced in 25.5.2 and 26.3.2.

Operating System: Windows 11, build 26200

GPU and Driver:

• NVIDIA GeForce RTX 4070 Ti Super, Studio driver 617.42
• Intel Graphics (integrated, Core Ultra 7 270K Plus, device ID 8086:7D67), driver 32.0.101.9150 (2026-10-08). Also reproduced on 32.0.101.6129 (2024-10-18).
• Renderer: Mercury Playback Engine GPU Acceleration (CUDA)

Video Format: Sony ILCE-7M4 (A7 IV), XAVC S, H.264 High Profile @ L5.2, 8-bit 4:2:0, 3840×2160, 50p, LPCM 16-bit stereo, standard Rec.709 picture profile (not log). Sample clip and metadata XML available on request.

Project Size: [Approx. project file size, Production yes/no, number of clips]

Helpful Context

• All projects or only some? One project so far.
• New, empty projects? Yes
• When did it start? The system was migrated from a 12th-gen Intel platform (i5-12600K, Z690) to the Core Ultra 7 270K Plus (Z890) without a fresh Windows install.
• Preferences reset (Shift on launch, all four options): Same results.

Isolation tests

• Software encoding with hardware decoding on: artifacts still present, so the encoder isn't the cause.
• All hardware decoding and encoding off: clean.
• Intel decoding off, Nvidia decoding on, hardware encoding on: clean across a full export. This is my current workaround.
• Intel driver updated to 32.0.101.9150, Intel decoding back on: artifacts return.
• Transcoding one affected clip removed its artifacts, but they then appeared on a neighbouring clip, which points to a decoder issue rather than corrupt source files.