QuickBooks Online (QBO) will depend on the information given by your bank. I suggest contacting the Square customer support team. They can investigate why your transactions are not importing to your QBO account.
In the meantime, let's click the Update button a couple of times to refresh the connection between your bank and QBO. Here's how.
Go to the Banking menu or Transactions.
Click the Banking tab.
Locate your Square bank account and click Update a couple of times.