Hello there, @AndrewZychowicz.

Thank you for the quick response. Allow me to chime in and share some insight on how to make the messages and warnings pop up on the same screen. 

Some dialogue boxes may not appear on the screen you are working on. However, you can toggle it back to the right monitor or move it manually. This way, QuickBooks will remember where you previously place it. 

For example, if you have home page on your right monitor, and you select Invoices, the Invoices page may appear on the left monitor. If you wish to see it on the right monitor, just move it to the right screen, and that'll do the trick.

I've also attached a link for our support site for additional reference: Help articles for QuickBooks Desktop.

That should point you in the right direction today. Please know that I'm just a post away if you have any other questions about the pop-up messages in your QuickBooks. I'll be happy to help you further.