The standard invoice page appears to have disappeared from the standard menu’s on the IOS app & has been replaced with ‘Paid Invoices’. Any ideas on how to resolve this?

I appreciate you for giving this detailed information, @barry41. Allow me to help you manage your invoices in the app.

To begin with, let's make sure you're using supported mobile operating systems.

 For Apple devices, it must be running iOS 11.1 or newer. 

• Safari browser. Note: Make sure Private Mode is off to allow cookies.
• Other browsers, such as Chrome and Dolphin, may work but aren't officially supported.

For more details, refer to this link: System requirements for QuickBooks Online, Accountant, Payroll, and QuickBooks Self-Employed. 

In the meantime, we can reset the app's cache to refresh the connection.

I'll guide you on how:

1. Select the menu icon.
2. Then choose Help & Feedback. 
3. Next, click Refresh Data and select Refresh. 

Also, you can learn how to make quick changes to invoice templates while you're on the go. Please read this article: Customise invoices on the QuickBooks Online mobile app.

If the issue persists, I recommend reaching the Phone support team. This way, they'll use specific tools to pull up your account and further check the root cause of the issue. 

I'm always here to help if you have any other concerns about managing invoices in your QBO app. Keep safe.