The numbers are catching up
Facebook doesn't stop delivery instantly and reports spend with a delay. Today's numbers in AdFleet are cached for 5 minutes — hit "Refresh" and check the object's status, not just its spend.
Paused at the wrong level
An ad is paused but others in the ad set keep running; an ad set is paused but the campaign has more. Pause at the level that's spending.
"Pause account" only touches AdFleet's campaigns
Campaigns created by hand in Ads Manager aren't stopped by it (/help/pause-account) — stop them in Stats.
AdFleet can't send the pause
A profile check (#31 / 3858385), "API blocked (#200)", a dead token or "Don't poll" — AdFleet sends no requests at all for that token or account, pauses included. Stop it in Ads Manager (/help/account-stops).
The pause wasn't confirmed
"Outcome unknown — check Ads Manager", or "stop not confirmed" on a canceled launch — Facebook's answer was ambiguous. Check in Ads Manager.
Someone turned it back on
An auto-rule with "Turn on", or a teammate. Look at the "Trigger log" and "Incidents" → "Change timeline" — they show who and when. "Notify only" and the burnout signal never stop anything by themselves.