I am trying to link our bank accounts, but all transactions are not connected with QuickBooks, and just some transactions are linked. Does anybody know how to fix this?

You can use MT Online or one of the converter tools (e.g csv2qbo @ $60 one time license) as a workaround.

https://www.moneythumb.com/?ref=110

Hi there, 

Thanks for joining the QuickBooks Community. I'll be happy to provide the info you need so you can move forward with your work. 

In order to keep your transactions updated I recommend manually uploading the transactions. After manually uploading you can match your transactions using the steps provided in this article. You also have the option of setting up bank to automatically categorize the transactions from the manual upload. Here's an article with more details on that. In case you come across duplicate transactions, you can delete them by following the steps below:

1. Navigate to the Banking menu.
2. Click on the For Review tab.
3. Select the checkbox of the transactions to exclude.
4. Hit Exclude.

Let me know if you have other questions. I'm here to steer you in the right direction.