Thanks for bringing this matter to our attention and for the detailed information about your supplier payments in QuickBooks Online (QBO), @4Crawler. Let me guide you on the actions you need to help take care of this issue.

For the time being, there aren't any reported cases of declined vendor payments in QBO. Based on your description, it seems that the error is caused by the browser's collection of data over time from frequent page visits. To isolate this matter, you can perform some troubleshooting steps.

You can start by pulling up your QuickBooks Online (QBO) account using a private browser (incognito). Here's how:

• Press Ctrl + Shift + N (Google Chrome)
• Ctrl + Shift + P (Firefox)
• Control + Option + P (Safari)

Once signed in, go to the + New button and pay your supplier invoices (bills). For the detailed steps, you can refer to this article: Pay bills in Online Bill Pay.

If you're able to do so, return to your default browser and clear its cache. This will refresh the system and remove older data that causes viewing and performance issues. However, if this matter continues, I'd recommend using other supported browsers.

In case the error persists, I would encourage you to reach out to our Customer Care team. The Community is a public forum, and we'll need to collect some personal information to pull up your account. They have the tools to investigate why your supplier payment got declined and guide you with a fix. To do this, here's how:

1. Sign in to your QBO company.
2. Go to the Help (?) menu.
3. Select the Search tab.
4. Click the Contact Us button.
5. Enter a brief description of your concern in the What can we help you with? field.
6. Select Continue.
7. Choose a way to connect with us (Send a message or Get a callback). 

Also, to further guide you in managing your suppliers, paying expenses and bills, and inventories in QBO, I'd recommend checking out one of our Help pages: Expenses and Vendors Help Articles. It also includes topics about vendor credits and purchase orders, to name a few.

Please let me know in the comments if you have other concerns about paying supplier invoices and managing expenses in QBO. I'll gladly help. Take care always, @4Crawler.