Thanks for sharing your experience when logging into QuickBooks Online (QBO) using your mobile device, @1817designs. With that, I can share some insights about Two-Step Verification on mobile devices.

Two-factor authentication works as an extra layer of security upon logging into QuickBooks. Even if you've turned it off from your account settings, it'll still ask for a code sent via email or mobile number if it's your first time logging into a specific device (i.e., PC and mobile devices).

With your device (mobile), access your account on a regular browser or through the QBO app, don't use Incognito (private browser). This will trigger the program to generate a code because it won't save any history. Then, allows the cache to save site settings or memorize account history. Just make sure there aren't any third-party apps that will prevent QuickBooks from doing so.

However, if this matter persists after following the suggestions above, I would encourage you to contact our Customer Care team. They can securely pull up your account, further investigate the cause of the issue, and guide you with a fix. Here's how:

1. Sign in to your QBO company.
2. Go to the Help (?) menu.
3. Select the Search tab.
4. Click the Contact Us button.
5. Enter a brief description of your concern in the What can we help you with? field.
6. Select Continue.
7. Choose a way to connect with us (Send a message or Get a callback). Make sure to initiate contact during support hours. 

Also, to further guide you in managing your QuickBooks account's data and security, I'd recommend checking out this article: Help Articles for your QuickBooks account. It also includes topics about user management and company info, to name a few.

Please don't hesitate to keep me posted on how it goes in the comments below. If you have other concerns about two-factor authentication in QBO, I'll gladly help. Take care, and I wish you continued success, @1817designs.