I know it’s difficult to remember exactly what you did when you didn’t know while you were doing it that remembering would be important later. There are a couple aspects of Manager’s underlying design at work in this process.
The first is that the program is pathologically opposed to losing data. Since you imported the statement, the data goes somewhere rather than falling on the floor. If the transaction is incomplete or unbalanced and can’t be fully resolved for any reason, that somewhere is Suspense.
The second is that inputs are not recorded, whether you’re working on a form, a setting, or anything else, until you click Create or Update (Bulk Update in this case). So if you’re creating new bank rules on the fly from the listing of uncategorized transactions, you’re actually still in the middle of a process. During that process, the program will show you matches of transactions to newly created rules, but doesn’t actually update them or save the new rules until you click Bulk Update.
So, what probably happened is that when you defined the bank rules, you didn’t actually create them. If this happens again, and you’re positive the rules are in existence, that suggests a mismatch in the cash account name or description, possibly through some font discrepancy or an extra space.