Hello there, vacaremodeler. When transactions stop appearing in QuickBooks Solopreneur, they may have been accidentally excluded. You can review these by navigating to the Bank Transactions tab.
Click the button in the right-corner and select Show excluded. To review if there are excluded transactions.

If transactions are still missing, you can filter them by date, set the date range from September 1st to September 30th to ensure all transactions during that timeframe are visible. I also recommend checking the bank connection in QuickBooks to confirm it is properly linked. Additionally, verify with your bank if there are any ongoing maintenance tasks.
If no issues are found with your bank and the connection appears fine, you can manually import the missing transactions into QuickBooks to keep your records up-to-date.
If you have any further questions or need assistance with QuickBooks, feel free to click the Reply button.