I can help you get your vendor names listed as an option when entering Journal Entry.
To single out this concern, let's try to verify if the vendor has an active status. Vendors who have inactive status doesn't show up in the list when you create a journal entry.
Go to Expenses from the left menu.
Select the Vendor Details tab.
Check the status.
If the status is active but you're still unable to see the vendor on the list, we can perform some basic troubleshooting steps to resolve this. Let's start with an incognito window to determine if it's the browser that's causing the error.
Google Chrome: press Ctrl + Shift + N
Mozilla Firefox: press Ctrl + Shift + P
Internet Explorer: press Ctrl + Shift + P
Safari: press Command + Shift + N
If it works, try clearing your browser's cache. This deletes temporary internet files and data that's causing unexpected performance in the product. Otherwise, you can also try using a different browser to be thorough. Changing to a different browser helps refresh your QuickBooks.
If none of these steps works for you, I recommend getting in touch with our Care Support Team so they conduct further investigation as to why you're unable to see the vendor names on the journal entry.
Should you have any other questions working with journal entries in QuickBooks Online, just reach out to me and I'll be here to answer them for you.