chromium build on steam flatpak stuck on loading screen

[dreamyukii]

Details

when launching chromium build using steam flatpak,it just stuck on loading screen, steam overlay seems not working too both 32/64 bit build

Steps to reproduce

1.launch garrys mod using steam flatpak 2.and stuck on loading screen

[robotboy655]

Probably duplicate of https://github.com/Facepunch/garrysmod-issues/issues/4677

[ImBearChild]

Probably duplicate of #4677

This issue is related but won't fix the flatpak one. Flatpak prevents unprivileged usernamespaces inside the bwrap (no matter what the kernel settings are), and the chromium on flatpak is patched. So maybe there's something like --no-sandbox option for CEF, considering that flatpak is some kind of sandbox itself...