Hi @Bear , the quota applies to that particular Web App. I've tested a similar scenario in my environment: one free-tier Windows App Service Plans with 5 web apps. Each of the web app shows similar quota page like this:
Shortly after I created the fifth web apps, all of the web apps shows "HTTP Error 403 - This web app is stopped".
I checked Azure Monitor for metrics of "Memory working set" for all of my web apps:
I put red arrow around the time I noticed all of my web apps were stopped.
I think your case is the same, it's the memory quota that caused your web apps to stop.
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