Having issues with your customer and vendor drop-down list not working can be frustrating. Are you trying to select your customer or vendor at the time you're creating transactions? If that's the case, there are actionable steps that we can take to resolve this issue, Sammy.

Sometimes, this happens because of browser-related issues, such as data cached by the software becoming outdated or improperly saved after a system update or change. If your customer or vendor list has been updated, but the cached data does not reflect the changes, the drop-down list may display an incomplete option or may not display any information at all.

You can clear your browser's cache to make sure the browser loads that most recent, updated version of the website. At the same time clear Intuit-specific cookies from your browser to fix performance or data display issues. 

However, if the issue continues, you can try switching to a different browser since not all browser render websites the same way. Some browsers may interpret the code or features of a website differently leading to display issues.

If you have any other concerns or additional questions related to your customer and vendor list, don't hesitate to keep in touch. We're always around to help you.