Re: I have lost all the functionality in the invoicing link on the left hand menu on my ipad.
Thank you for posting in the Community. I'm here to help you get back on track regarding the invoicing link in QuickBooks Online.
We've received reports from other users about the iPad mobile app crashing when clicking on the Sales panel at the left side. The investigation number for the issue is INV-23398.
The affected users are advised to use a supported browser in the meantime while our product engineers are working for a fix. Please also reach out to our Support Specialists to be part of the affected users and to be able to receive updates via Email.
If you're referring to a missing invoicing on the left side menu, I recommend uninstalling and reinstalling the app again. By doing so, we'll be able to determine if the problem is related to the release version of the app.
If you need additional assistance from me with the mobile app, please don't hesitate to post a response. Any screenshots or further details will ensure a timely solution.