Hello there, @mattclarkebrickw.
Our engineers have tagged this issue as resolved. I'm here to back you up and make sure you're in working order.
Let's start by submitting your CIS in a private window. It's the greatest location to figure out why you can't send CIS. To open one, use the following keyboard shortcuts:
· Google Chrome: Ctrl + Shift + N
· Mozilla Firefox: Ctrl + Shift + P
· Microsoft Edge: Ctrl + Shift + P
· Safari: Command + Shift + N
You can also use Google Chrome, Mozilla Firefox, Safari, or Microsoft Edge as an alternative browser.
I've also included these articles about CIS submission: CIS in QuickBooks Online.
If the issue persist, you can reach out to our contact support. They will also provide you with the necessary information regarding your concern.
Please let me know how things proceed on your end. I want to make certain that this issue is fixed. Keep yourself safe!