Hi there, @Finless.
Let's get the bills to show in the Pay Bills window so you can get back to working order.
It's possible that your software isn't updated. Let's reset the update release to get this fixed. Here's how:
I'm adding this article for more details: Update QuickBooks Desktop to the latest release.
However, if you get the same result, I suggest opening the bill and process the payment from there.
Keep in touch if you need any more assistance with this, or there's something else I can do for you. I've got your back. Have a good day.