Unable to import second instance of brokerage (completely different accounts/credentials/data)

Using TT Home & Business desktop software. When importing Fidelity #1, it imports as expected, and shows me what it received. I click OK, and it's done. I then go to 'import another brokerage' and tell it Fidelity again (this is a second, completely unrelated account, with no relationship to the first one, different login, different password, different everything... the two accounts are 100% separate, and don't know of each other's existence). It pops open the login page, where I enter Fidelity #2 credentials. It then pretends to download, and when "done" it presents me with the SAME items it already downloaded before when I did Fidelity #1. If I click the OK button to import it anyway, there is only one instance of Fidelity in the resulting import review page. The second account simply is not imported. But worse, it pretends that it did... but that is exposed as an obvious error because the Fidelity #2 account has significantly different data (eg, #1 has 1099-DIV of about $50, and #2 has 1099-DIV of about $35,000). Same vastly different numbers for 1099-INT, 1099-B, etc.