Hi there, jmjohnnybgood.
I'm glad to see you here in the Community. I'm here to share some information about how the dark line on the register works in QuickBooks Online (QBO).
The dark line only appears when you have new transactions added to the register. Right now, configuring how the line separator works is unavailable.
We want to hear your feedback about this feature. Our goal is to improve the product based on what works best for your business. I recommend you send your suggestion directly to our product engineers.
You can send them directly through the link attached below:
The Community is here anytime you need help. Let us know by leaving a comment below, and we'll be sure to get back to you.