Why do my transactions keep disappearing after not pending anymore?

Let me help you with the bank transactions, 541dieseladdicts.

In QuickBooks Self-Employed, there are filters which could be the reason why some transactions aren't showing. From the Transactions tab, you can set the Type and Account drop-downs to All. That way, all transactions you've added will appear. You can also change it anytime to see the transactions based on the category.

Also, another reason is that the bank has been disconnected or the CSV file has been deleted. Once the source of those transactions has been removed or disconnected, the transactions will also be deleted permanently and we can't undo it. The only way to bring it back is to import it again.

I've added this article for your reference about Schedule C Categories breakdown.

Please reply to this thread if you have more questions. I'll be glad to assist you.