Let me help you fix this so you can get back to your business, @nutmegthegreat.
Sometimes local cache stored in your browser can cause unexpected behavior with QuickBooks Online (QBO). This can be the reason why you get the error message Full Service Set up Not Complete when switching the QBO Payroll subscription.
However, there are troubleshooting steps you can use to fix this problem. Let me show you the process.
First, log out to your account and log back in using a private window. This is a special mode that doesn't save your browsing history. Simply press these following keyboard short cut keys to access it:
Press Ctrl + Shift + N (Google Chrome).
Ctrl + Shift + P (Firefox).
Control + Option + P (Safari).
If you're able to get rid of the error message, then let's clear the cache in your web browser or try using a different supported browser. This might be a temporary issue with QuickBooks and the current browser that you use.
If you're still getting the error message and unable to view your tax information, you can reach out to our QBO Payroll Support Team. This way they can check your account to find out what's causing the behavior.
I'm always here to help if you have any other concerns or questions. Just tag my name in the comment section, and I'll get back to you as soon as I can. Have a great weekend.