If you are a PPC pro then this article might be a useful read – https://www.ppchero.com/google-policy-ad-disapprovals-a-story-of-false-flags/
If you are a business owner managing your own PPC, then most probably you may not have time to check your Google ads account everyday. In such a case, do follow the “Email Notifications” section of the above article, to set up email notification for ad disapproval.