[Flatpak] internal decoding error with AV1 on RTX 40-series (Brave)

[Lukestar46]

Describe the bug
When attempting to play AV1 video in Brave (Flatpak) on an RTX 40-series card, the decoding fails with an "internal decoding error" and falls back to software (dav1d). H.264 decoding works perfectly with the same flags.

System Info

• OS: Bazzite 43 (Fedora Atomic / Universal Blue)
• GPU: Nvidia RTX 4060ti
• Driver: [590.44.01]
• Browser: Brave (Flatpak)
• Installation Method: Flatpak

Reproduction Steps

1. Install Brave via Flatpak.
2. Apply environment overrides: LIBVA_DRIVER_NAME=nvidia, NVD_BACKEND=direct.
3. Apply flags: --enable-features=VaapiVideoDecodeLinuxGL, --use-gl=angle, --use-angle=gl.
4. Play an AV1 video on YouTube.

Expected Behavior
Hardware decoding should engage (VaapiVideoDecoder).

Actual Behavior
Video falls back to software. Terminal log shows:
vaEndPicture failed, VA error: internal decoding error

Workaround
Installing enhanced-h264ify browser extension and blocking AV1 and VP9 (forcing H.264) results in successful hardware decoding (VaapiVideoDecoder) with the exact same flags.

[maksimgurenko]

same here brozer but on arch