Is anyone else having problems with customers suddenly not being able to view their payment options on their invoices?

Thank you for posting your concern here in the Community, @gary122. Let me share more information about the payment option in QBO.

It's possible that the payment option on your invoice was disabled. We must ensure that this option is enabled before sending the invoice to your customers. Follow these steps how:

1. Go to the Invoices, and open the invoice you've sent.
2. Click the Manage tab.
3. Select Payment options.
4. Turn on the payment you want.
5. Hit Review and Send.

After doing this steps, we can now resend the invoice to your customer. If they still encounter the same issue, have them view the invoice through incognito window. When your customer confirm that they can view, we can go ahead on clearing cache and cookies on browser. I recommend also on utilizing another supported browser. It can help us identify if the issue is specific to the current browser.

Moreover, let me share this article if you want to know how to customize your estimates: Customize invoices, estimates, and sales receipts in QuickBooks Online.

Let me know if you still have questions about your invoices and payments. We'll be here 24/7 to assist. Have a great day, and take care always.