Hi I was wondering why a few times I've sent my invoice and its not been highlighted in green saying its sent when they actually have been?

Let me share some information about invoice status, @kborchardtbuilde.

An invoice status will update (from Opened to Sent to Viewed to Paid to Deposited) once there's an activity performed for that specific transaction. It'll automatically recognized it once your customer viewed the invoice. 

If your customer has verified that they already opened and viewed the invoice and the status is not updated from your account, I suggest clearing your browser's cache. It's possible that piled-up cache in your regular browser caused this unusual behaviour.

To resolve this, First, you'll have to sign in to your QBO account using a private browser. This helps isolate the issue since it doesn’t store data in the cache. Here are the following keyboard shortcuts: 

• Safari: Command + Shift + N
• Mozilla Firefox: CTRL + Shift + P
• Google Chrome: CTRL + Shift + N
• Microsoft Edge: CTRL + Shift + P

If it works, here's how to clear cache and cookies to fix issues when using QuickBooks Online. Restart your browser right after. You can also proceed by using other browsers if the steps above don’t work.

Refer to the following article for more information about common statuses that you might see on invoices: Track the status of invoices in the QuickBooks Online mobile app.

Once you've received their payment, here's how to record the payment to update the status to paid and deposited: Record invoice payments in QuickBooks Online.

I'm always here if you need more help with your invoices. Let me know in the Reply section below. Keep safe and enjoy the rest of the day!