Your system information

• Steam client version: Build 1773426488
• Distribution: CachyOS (Arch-based), kernel 6.19.9
• Opted into Steam client beta?: No (have tested on beta)
• Have you checked for system updates?: Yes — fully updated
• GPU: AMD Radeon RX 7900 XTX (amdgpu)
• Desktop: KDE Plasma 6.6.3, Wayland
• PipeWire: 1.6.2
• KWin: 6.6.3

Please describe your issue in as much detail as possible:

When any application has an active XDG ScreenCast portal session (org.freedesktop.portal.ScreenCast), Steam's SharedJSContext creates popup views that open empty browser tabs with data:text/html,%3Cbody%3E%3C%2Fbody%3E. This happens whenever the Steam window toggles visibility (WasHidden 0/1), e.g. during alt-tab, game launch, or notification popups.

Steam should ignore other applications' portal sessions. The ScreenCast session belongs to a third-party app, not Steam.

What happens: steamwebhelper detects the portal activity and creates a SteamBrowser popup with an empty body. This popup appears fullscreen over the game, breaking gameplay. It floods dbus and crashes background applications (discord/steam etc)

From webhelper.txt:

  [2026-03-23 20:19:22] SharedJSContext-'SharedJSCo': CreatingView 1 browser:2 popup:196610 url:data:text/html,%3Cbody%3E%3C%2Fbody%3E
  [2026-03-23 20:19:24] SteamBrowser-'data:text/': WasHidden 0: (1, 92) 2626x1355

Steps for reproducing this issue:

1. On KDE Wayland with PipeWire 1.6.x, start any app that creates a persistent org.freedesktop.portal.ScreenCast session (e.g. OBS, any screen capture tool using ashpd/libportal)
2. Launch a game via Steam (Proton or native)
3. Alt-tab or wait for a Steam notification — the empty data:text/html browser tab appears, sometimes covering the game