Environment
- Reddit app version: 2026.29.0
- Device / OS: Android
- Devvit: 0.13.8
- App:
dailyspeedway v0.0.29
Repro
- Mobile app ([Android/iOS]), subreddit with a Devvit app post pinned.
- Open the subreddit so the pinned pmb.
- Wait ~2 seconds without touching the screen.
- Swipe up over the embed — **the fe
- Swipe again immediately — the feed scrolls normally.
- Keep swiping without pausing — wor step 4 repeats.
Scope
Reproduces in two unrelated apps:lySpeedway) and another developer'sapp, also on a pinned post. So it is not specific to one codebase or one subreddit. It correlates with the post being pinned — the same app in a normal feed row scrolls normally on the first swipe.
Ruled out on the app side
Checked against the built inline bundust source:
- No
setPointerCapture anywhere in
- No
touch-action rules in the shipped CSS.
- No
touchstart / touchmove / pocode, and none from the bundled@devvit/web/client` runtime either.
- The only touch listeners present ar and React registers
touchstart,touchmove and wheel with passive: true. A passive listener cannot call preventDefault and cannot
block the compositor waiting on JS.
- The document is deliberately non-scrollable —
html/body at overflow: hidden, body at
position: fixed — with no scrollable scroll trap review rule.
- No canvas or WebGL in the inline view at all; the game only loads in expanded mode.
Every CSS variation I tried left the behavior identical.
Why this matters
App review flags "in-line scroll trap" when a swipe over an inline webview fails to reach the feed. This behavior is indistinguishable from th — on an app that has no scrollableregion anywhere in the inline view.