Pop up / overlay alerts don't always work

[BrentW89]

I turned on your newer feature to overlay notifications on the screen for x seconds. It works on my windows laptop but not on my tablets, which run fully kiosk. Not sure if fully kiosk is interfering. I can say I've had browser mod and bubble card pop ups working with fully kiosk, so maybe there's a tweak that can fix this? Or a setting in fully kiosk?

On my windows 11 laptop running Edge, it likes to repeatedly display notifications at times, sometimes multiple alerts one after the other. At first I throught this was due to a home assistant server reboot, but I think it happens at other times so not really sure yet. It just happened this morning with an alert from yesterday I never pressed hold to dismiss.

[MattDBZA]

I am seeing the same issue:
Overlay notifications work correctly when viewing on my desktop browser but on a phone or tablet they dont display. I tried on dashboards running kiosk and dashboards not running kiosk on those devices with no success

[djdevil]

Thanks for the detailed description! Two separate issues here — let me address each:

Fully Kiosk (tablets) — overlay not showing at all

The overlay injects a

directly into document.body using a setInterval watcher. Fully Kiosk's browser has a stricter security model than stock Chrome/Edge and can block or sandbox certain DOM operations on the top-level document.

To help me diagnose, could you check:

Open the browser console in Fully Kiosk (Settings → Advanced Web Settings → Enable Remote Debugging, then connect via chrome://inspect) and look for any JS errors when an alert should have fired
Is "Allow JavaScript" enabled in Fully Kiosk settings?
Is overlay_mode: true set on the card config that lives on the same dashboard view the tablets show, or on a different view?
Windows/Edge — alerts firing multiple times / old alerts reappearing

The overlay watcher tracks which alerts have already been shown in memory (resets on page refresh or HA restart). If HA was restarted or the browser tab was refreshed while an alert was still active, the watcher treats it as a new trigger on the next tick.

For the "alert from yesterday" case: if the entity was still in the triggered state when the page reloaded, the watcher would fire it again on the second tick after reload — this is expected behaviour. The fix is to hold the overlay banner to permanently dismiss it (which snoozed it card-side), or set auto_dismiss_after so the alert clears itself.

That said — if you're seeing it fire on Edge without a page reload, could you share:

Your card YAML (especially overlay_mode, auto_dismiss_after, on_change settings)
Whether the alerts that re-fired have on_change: true
Roughly how often the repeat happens — every few seconds, or hours apart?