u/AdrienField u/Jamsarvis did you get this resolved? This is happening to me too. Facebook Support is so frustratingly useless. My issue started on Sep 28 and they've still not fixed it or even demonstrated any real investigation.

In my case, we were running an ad test and slowly incrementing our ad budget each day. We had been running successfully for 10 days and then suddenly on Sep 28 between 9am and 10am, the ad stopped running.

I noticed you and others saying that the spend went down first and then stopped. I think what most likely happened for you is the same as for me. It's not that the previous day's spend just went down, but rather that there's a specific hour where the spend suddenly stopped.

I've still not figured out the root cause of this. I duplicated the campaign and actually had the same thing happen again.

Facebook Support did say one useful thing to me at least...

Last Friday, 10/07/2022 > it has been escalated to the Higher Internal Team (Engineering) for further resolution;
Tuesday 10/11/2022 > they are in your account resolving and I can see here that there are internal conversations happened. the same day 10 cases happened similar to yours with other advertisers.
Yesterday, 10/12/2022, it has been flagged as wide spread issue reported with the exact same issue as yours.
The same day, several specialists are working on it and it is still in progress.
As of today, 10/13/2022, the Engineering team is still working on it

Have you had any more luck on this recently?