Hi skmajowski,
Welcome to the Community. I'll be glad to guide you in the right direction so you can sync your transactions with ease using QuickBooks.
In order to fix the issue you've described, I recommend disconnecting and re-connecting your bank connection. You can disconnect a bank account by navigating to your Transactions page in QuickBooks > click on the bank in question > select the pencil ✎ icon > Edit account info > hit the Disconnect this account on save checkbox. From here you can click Save so your changes are saved and that the bank is disconnected. Here's a helpful guide that shows you how to: Disconnect accounts connected to online banking in QuickBooks Online.
Give this a try and let me know how you make out. I'll be a message away in case you need additional support.
