The main invoice doesn't reflect in the project overview, even though it's there in the transactions tab of the project. I even deleted the invoice and logged it in again

Hi there, @melkhafif.

Thanks for visiting the Community today. Let's first review that the main invoice is properly mapped to the Project so it will reflect in the Project Overview report. 

I'd suggest you review the filters on the Transactions page for the Project. Here's a brief video for your visual reference:

If the issue persists, I'd recommend using an incognito or a private browser to identify a browser-related problem. Here's how: 

1. Launch Google Chrome as your main browser.  
2. Press these keys together, CTRL+SHIFT+N. 
3. Log in to QuickBooks, and run the Project Overview report. 

If that works, go back to the main browser and follow the steps to clear its cache. If it's still an issue, try using a different supported, updated browser. 

For future reference, read through this article: QuickBooks Online Projects. It helps you learn about tracking projects and stay organized while managing your work and see your progress. 

Feel free to message again. I'll be looking forward to helping you more.