Propeller Ads may keep stopping for a few reasons. You could be experiencing issues with your internet connection, which may interrupt the ad service. If your website is not receiving enough traffic or the traffic is of low quality, the ads may stop showing. Another reason could be if your account has violated Propeller Ads' policies, leading to temporary suspensions. Certain ad formats may not be compatible with your website, causing interruptions. Checking the settings, ensuring compliance with policies, and improving your traffic quality can help resolve this issue.