I'm here to point you in the right direction to help you put the missing transactions from 2019 back into your QuickBooks Online account. There could be a few reasons that this happened within your account. Example: Connection lost between the bank and QuickBooks, behind the scenes error message that you may not be able to see, etc.
The best way to get these transactions back is to import them into QuickBooks with an Excel (CSV.) file. Here's how:
Note: Before doing the steps below, go to your bank website and download the transactions that you're missing into an Excel (CSV.) file. If you have any trouble along the way you can check out the link provided above.
Go to the Banking tab and then select the Banking section.
Press File Upload in the Update drop-down box.
Pick Browse and choose the file you downloaded from your bank.
Click Open and then Next.
Find the bank or credit card account from the QuickBooks Account drop-down list, and then hit Next.
Select a Date, Date Format, Description, and Amount. Note: You can select 1 or 2 columns for the amount if separated as Credit and Debit.
Check the boxes of the transactions you'd like to import.
Click Let's go! when the import is complete.
It's that easy! I also recommend contacting our Support Team to make sure that this issue doesn't persist in the future. They have additional tools to look further into your account to see why this happened in the first place.
If you have any other questions, don't hesitate to ask. Have a wonderful day!