Hi Josh,
If you navigate to your web app in the Azure portal, are you able to click the Start button to start it? Does it give you an error? You may check Activity log blade for information on why it was stopped.
Have you checked your web app -- App Service plan -- Quotas blade to see if any quotas have been reached? Some SKUs have limits which can cause your web app to be stopped.
If you haven't already, please review below article for common reasons why your web app may be stopped:
Azure Web Apps: “Error 403 - This web app is stopped..”
Please click Accept Answer and upvote if the above was helpful.
Thanks.
-TP