Why won't my bank show all of the transactions? It's connected, and I tried to import a CSV that shows all, but it is ignoring many

Good work on importing files, @brendan14. I'll share some possible reasons why some data aren't showing after importing them.

Could you let us know which bank is causing you challenges? In this method, I may look over here and see if there are any related issues. Any additional information is much appreciated.

If your file's too big, try shortening its date range and downloading transactions in smaller batches. Since QuickBooks only allows 350 KB, ensure the file doesn't exceed that limit.

I'm also adding this article for more insights into manually importing transactions in QuickBooks Self-Employed. 

Moreover, if you're importing older transactions, you need to sort the list by date before you get the transactions from your bank. Take note of the oldest transaction date in the account to avoid duplicate transactions. See this article for the method under step #1: Add older transactions to QuickBooks Self-Employed.

I'm more than happy if you need assistance with a different task in QuickBooks Self-Employed. You can put my name in the comments section if you need the complete tracking of your quarterly income and spending.