AdMob Rewarded Ads Load but Never Show in Unity Android Build - Activity Lifecycle and Mediation Waterfall Fix - How to Fix

If your Unity Android logs say the rewarded ad loaded, but the ad never appears when you call show, you usually have a lifecycle or mediation-state mismatch.

This guide gives you a fast, repeatable fix path.

Problem

Typical symptoms:

OnAdLoaded callback fires
no crash, but no ad UI appears
reward callbacks never run
issue reproduces more on resume, scene switch, or low-memory devices

Root Cause

In most projects this happens because one or more of these conditions are true:

Show() is called before the app returns to a valid foreground activity state
the ad object is stale after pause/resume or activity recreation
mediation adapter is initialized late or not ready in the selected waterfall slot
show call is triggered off the Unity main thread timing path
preloading logic races with scene transitions and invalidates the loaded instance

Quick Fix Checklist

Run these first:

initialize Mobile Ads SDK once at startup and wait for completion callback
keep one rewarded instance per placement and replace it after every show attempt
show ads only when app focus is true and Android activity is resumed
verify all mediation adapters are present and version-aligned
test with AdMob test IDs and adapter test mode before production IDs

Step-by-Step Fix

Step 1 - Gate show calls behind lifecycle-safe conditions

Only call Show() when all conditions are true:

app is in foreground (OnApplicationFocus(true))
no scene transition is in progress
rewarded instance is loaded and not yet consumed

If you trigger show from button press immediately after resume, defer one frame and re-check focus.

Step 2 - Recreate rewarded object after each show attempt

Treat rewarded ads as single-use objects.

After show success, show failure, or dismissal callback:

null old reference
create a fresh rewarded ad instance
rebind callbacks
request next load

This avoids “loaded but not showable” stale-object states.

Step 3 - Validate mediation waterfall readiness

In AdMob + mediation setups:

open Ad Inspector on device
check adapter status for each configured network
confirm no adapter version mismatch
verify placement is not blocked by consent or region policy

A loaded top-level ad callback can still fail to show if the selected waterfall candidate is not actually show-ready.

Official references:

Step 4 - Ensure show path executes on the correct runtime timing

If you bridge events through async tasks, restore control to Unity main gameplay flow before calling show.

Use one dedicated ad manager that serializes:

load state updates
readiness checks
show requests
post-show reload

Do not scatter Show() calls across multiple scene objects.

Step 5 - Harden pause/resume behavior on Android

On Android, activity changes can invalidate show timing.

When app resumes:

re-check focus
confirm current rewarded instance is still valid
if uncertain, discard and preload fresh
re-enable UI trigger only after load callback confirms ready

This prevents silent no-op shows after returning from background.

Verification

Use this validation loop:

clear app data on test device
run with test ad unit IDs
load rewarded ad
background app for 10-20 seconds, resume, then show
repeat across 3 scene transitions

Pass criteria:

ad UI appears on each valid show attempt
dismissal callback fires
reward callback fires exactly once
next load starts immediately after dismissal

Alternative Fixes

If issue persists:

Alternative A - Disable mediation temporarily

Use pure AdMob test inventory only.

If show works, the issue is in adapter configuration, not core lifecycle flow.

Alternative B - Reduce initialization fan-out at startup

If many SDKs initialize together, delay non-essential SDK startup until after first rewarded preload.

Alternative C - Add show timeout fallback UX

If show does not start within a short timeout window, cancel and return control to player with a retry button.

Prevention Tips

centralize ad state in one persistent manager object
log load, show, dismiss, reward with build ID and scene name
run one Android lifecycle regression test before each release
keep mediation adapters updated in lockstep with Mobile Ads SDK version
avoid manual duplicate initialization in multiple scenes

FAQ

Why does OnAdLoaded fire but ad still does not show

Load success only confirms inventory fetch, not that your runtime state is valid at show time.
Lifecycle or stale reference issues can still block display.

Should we preload multiple rewarded ads to avoid show failures

For most indie projects, one controlled instance per placement is safer.
Multi-instance preload adds race complexity unless you implement strict queue ownership.

Can consent flow block rewarded show even after load

Yes. Region-specific consent and privacy state can affect mediation eligibility and final show path.
Verify consent state and adapter status together in Ad Inspector.