Thanks for joining the Community. It's important you're able to create journal entries without running into issues. Rest assured, I'll be happy to give you a hand so you can get back to doing what you enjoy.
When it comes to journal entries, I recommend making sure your entries don't result to the multiplication you're experiencing. Here's a helpful article that shows you how to: Create journal entries in QuickBooks Online. In case you're experiencing browser-related issues, I suggest clearing cache and cookies. Clearing cache and cookies is a great way to clean your browser allowing it to work more efficiently. Here's an article that shows you how to do that: How to clear cache and cookies.
Let me know if this info helps. I'll be one message away in case you additional further assistance.