We can perform some troubleshooting steps for you to add or edit a vendor into your account, @lizraimo.

We understand the importance of ensuring that QuickBooks Online (QBO) runs smoothly especially when managing purchase orders. We will provide you with some troubleshooting steps to help improve its performance.

Sometimes, a browser's cache data becomes full of frequent access to web pages or is damaged. When this happens, it causes odd behavior when adding or editing vendor information. Sign in to QBO using a private or incognito window to isolate this issue. This helps us confirm browser-related issues since this mode doesn't use the existing cache data. Let me show you how:

• For Google Chrome browser: Ctrl + Shift + N
• For Mozilla Firefox browser: Ctrl + Shift + P
• For Safari browser: Command + Option + P

If it works, go back to your regular browser and clear the cache to delete those temporarily stored files and browsing history. Removing this should fix the issue since the overtime collection of data can create corruption. We can also use supported, up-to-date browsers to roll out the possibility of a browser-related issue. 

For future reference, visit our QuickBooks Online Articles hub. You can search for topics related to your concern and get some steps to resolve any issues you may encounter. 

 Also if you have questions about purchase orders, please add a reply below. I'd be happy to assist you further.