Thanks for joining this thread, Zhanna2022.

I want to make sure you're able to show the open balance for your customer in QuickBooks Online. 

Since the troubleshooting steps mentioned above didn't do the trick, I recommend reaching out to a member of the QuickBooks Online Support Team. Agents have specialized tools, like the ability to share your screen, and will be able to determine what's causing the issue. Here's how to get in touch with the team:

1. Click the Help button in the top right corner.
2. Select Contact Us.
3. Enter Support in the field and choose Let's talk.
4. From here you can select to receive a callback at a time that's convenient for you, or begin a live chat session with an agent.

The following article provides these steps if you ever need them again in the future: QuickBooks Online Support

Please don't hesitate to reach back out if you have any other questions or concerns. Take care!