why is my supplier nvoice automatically being marked as paid when I enter it as a new invoice

Hi there,

Welcome to the Community. QuickBooks is designed to help you streamline your accounting. I'll be happy to share more and help steer you in the right direction. 

Based on the details you've shared, I suggest clearing cache and cookies on your browser. Doing this helps with fixing most browser-related issues. You can do this by following the steps in this article: Clear Cache and Cookies. I encourage you to give this.

Feel free to let me know what happens. I'll be here in case you have other questions.