Hi cma13,
I'm here to share more information about unlinking time in QuickBooks Online.
The moment you unlink time from an invoice, it remains open and will be moved to the Add to Invoice panel (left side of the Invoice page). The left panel lists all the open transactions under that same customer.
Furthermore, you can check this article about managing time in QuickBooks Online: Enter billable time by job.
You can always post in the forum anytime you have concerns about invoices.
