Game name: World of Warcraft (non-Steam game, run via Battle.net launcher)
Steam AppID: N/A (non-Steam game)
GPU: NVIDIA RTX 5080
Driver version: 595.58.03
Kernel version: 6.17.0-29-generic
System information: (paste your Steam system info here)
Proton version: Proton Experimental (also reproduced on GE-Proton10-34)
Symptoms:
When attempting to purchase a WoW Token from the in-game shop, the payment window opens with the "BATTLENET" title bar but renders completely blank. No error message is shown. The window can be closed and the game continues normally.
Reproduction:

1. Launch World of Warcraft via Battle.net through Steam/Proton
2. Log into a character
3. Open the in-game shop
4. Select WoW Token → click $20
5. Payment window appears with title "BATTLENET" but content is blank

Root cause from logs:
CEF-20260528T162012.log shows:
[ERROR:viz_main_impl.cc(152)] Exiting GPU process due to errors during initialization

Browser-20260528T162012.log confirms hardware acceleration is already disabled (enableHardwareAcceleration: false) yet the GPU process still launches and crashes. The page loads successfully (OnLoadEnd) but cannot be painted to screen.
Full logs: https://gist.github.com/truknightmare/1bf8cdc81efc659b89ea9d07bf438332