I’m missing all transactions from my business checking account from 7/6/2020 to 1/1/2021. All transactions are there since 1/1/2021, so the connection with my bank is currently updating.

Glad you've joined us here in the Community, @melissapetersenm.

I have some information about bank transactions. If this is your first time connecting your account, you can download up to the last 60-90 days of transactions. Other banks can go back as far as 24 months. However, you can use the import feature to download missing transactions. Let me walk you through the steps.

1. Sign in to your bank's website, and follow your bank's steps to download a CSV file.
2. Set a date range and go after the instruction to finish the download.
3. Open your QBSE account.
4. Go to Gear at the top. Then, choose Imports.
5. Select the account you want to import the transactions from.
6. Click the Import older transactions link. 
7. Tap Browse and locate the CSV file.
8. Tick Open to start the import.
9. Hit Continue until Finish.

Below is the image of Steps 4 and 6:

For details about importing transactions, check this guide: Add older transactions to QuickBooks Self-Employed.

In case you need help with other tasks in QBSE, browse this link here to go to our general topics with articles.

Tag me if you still have questions or concerns with bank transactions. I'll be around for you. Take care and have a lovely day.