Hello Naomi,
Welcome to our forum! Happy to see that you've started using it.
To view all invoices go to Customer Center > Invoices and ensure that your Filter By View is set to 'All Invoices'.
I think what is happening is that your transaction history in Method is not showing all transactions – this is a good thing since it doesn’t slow down your Method account (You can set the default transaction history to 31, 60 or 90 days if you like or even longer – keep in mind the longer it is set for and the bigger your QB file it will slow down Method. Instead if you just want to see all invoices follow the steps below.
In Method, go to QuickBooks > Synchronize > Show options per transaction type(Click here) > set invoices to 'All' by clicking on the down arrow next to 'Invoice'. Scroll to the bottom of the screen and click on Save Settings. Do a full sync. Let me know if you are now able to see all invoices. Also make sure the grid on your invoice screen is set to show “All Invoices”.
Let me know if this works for you.